1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819 820 821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847 848 849 850 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973 974 975 976 977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095 1096 1097 1098 1099 1100 1101 1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125 1126 1127 1128 1129 1130 1131 1132 1133 1134 1135 1136 1137 1138 1139 1140 1141 1142 1143 1144 1145 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172 1173 1174 1175 1176 1177 1178 1179 1180 1181 1182 1183 1184 1185 1186 1187 1188 1189 1190 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229 1230 1231 1232 1233 1234 1235 1236 1237 1238 1239 1240 1241 1242 1243 1244 1245 1246 1247 1248 1249 1250 1251 1252 1253 1254 1255 1256 1257 1258 1259 1260 1261 1262 1263 1264 1265 1266 1267 1268 1269 1270 1271 1272 1273 1274 1275 1276 1277 1278 1279 1280 1281 1282 1283 1284 1285 1286 1287 1288 1289 1290 1291 1292 1293 1294 1295 1296 1297 1298 1299 1300 1301 1302 1303 1304 1305 1306 1307 1308 1309 1310 1311 1312 1313 1314 1315 1316 1317 1318 1319 1320 1321 1322 1323 1324 1325 1326 1327 1328 1329 1330 1331 1332 1333 1334 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347 1348 1349 1350 1351 1352 1353 1354 1355 1356 1357 1358 1359 1360 1361 1362 1363 1364 1365 1366 1367 1368 1369 1370 1371 1372 1373 1374 1375 1376 1377 1378 1379 1380 1381 1382 1383 1384 1385 1386 1387 1388 1389 1390 1391 1392 1393 1394 1395 1396 1397 1398 1399 1400 1401 1402 1403 1404 1405 1406 1407 1408 1409 1410 1411 1412 1413 1414 1415 1416 1417 1418 1419 1420 1421 1422 1423 1424 1425 1426 1427 1428 1429 1430 1431 1432 1433 1434 1435 1436 1437 1438 1439 1440 1441 1442 1443 1444 1445 1446 1447 1448 1449 1450 1451 1452 1453 1454 1455 1456 1457 1458 1459 1460 1461 1462 1463 1464 1465 1466 1467 1468 1469 1470 1471 1472 1473 1474 1475 1476 1477 1478 1479 1480 1481 1482 1483 1484 1485 1486 1487 1488 1489 1490 1491 1492 1493 1494 1495 1496 1497 1498 1499 1500 1501 1502 1503 1504 1505 1506 1507 1508 1509 1510 1511 1512 1513 1514 1515 1516 1517 1518 1519 1520 1521 1522 1523 1524 1525 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538 1539 1540 1541 1542 1543 1544 1545 1546 1547 1548 1549 1550 1551 1552 1553 1554 1555 1556 1557 1558 1559 1560 1561 1562 1563 1564 1565 1566 1567 1568 1569 1570 1571 1572 1573 1574 1575 1576 1577 1578 1579 1580 1581 1582 1583 1584 1585 1586 1587 1588 1589 1590 1591 1592 1593 1594 1595 1596 1597 1598 1599 1600 1601 1602 1603 1604 1605 1606 1607 1608 1609 1610 1611 1612 1613 1614 1615 1616 1617 1618 1619 1620 1621 1622 1623 1624 1625 1626 1627 1628 1629 1630 1631 1632 1633 1634 1635 1636 1637 1638 1639 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664 1665 1666 1667 1668 1669 1670 1671 1672 1673 1674 1675 1676 1677 1678 1679 1680 1681 1682 1683 1684 1685 1686 1687 1688 1689 1690 1691 1692 1693 1694 1695 1696 1697 1698 1699 1700 1701 1702 1703 1704 1705 1706 1707 1708 1709 1710 1711 1712 1713 1714 1715 1716 1717 1718 1719 1720 1721 1722 1723 1724 1725 1726 1727 1728 1729 1730 1731 1732 1733 1734 1735 1736 1737 1738 1739 1740 1741 1742 1743 1744 1745 1746 1747 1748 1749 1750 1751 1752 1753 1754 1755 1756 1757 1758 1759 1760 1761 1762 1763 1764 1765 1766 1767 1768 1769 1770 1771 1772 1773 1774 1775 1776 1777 1778 1779 1780 1781 1782 1783 1784 1785 1786 1787 1788 1789 1790 1791 1792 1793 1794 1795 1796 1797 1798 1799 1800 1801 1802 1803 1804 1805 1806 1807 1808 1809 1810 1811 1812 1813 1814 1815 1816 1817 1818 1819 1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 1876 1877 1878 1879 1880 1881 1882 1883 1884 1885 1886 1887 1888 1889 1890 1891 1892 1893 1894 1895 1896 1897 1898 1899 1900 1901 1902 1903 1904 1905 1906 1907 1908 1909 1910 1911 1912 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922 1923 1924 1925 1926 1927 1928 1929 1930 1931 1932 1933 1934 1935 1936 1937 1938 1939 1940 1941 1942 1943 1944 1945 1946 1947 1948 1949 1950 1951 1952 1953 1954 1955 1956 1957 1958 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 2041 2042 2043 2044 2045 2046 2047 2048 2049 2050 2051 2052 2053 2054 2055 2056 2057 2058 2059 2060 2061 2062 2063 2064 2065 2066 2067 2068 2069 2070 2071 2072 2073 2074 2075 2076 2077 2078 2079 2080 2081 2082 2083 2084 2085 2086 2087 2088 2089 2090 2091 2092 2093 2094 2095 2096 2097 2098 2099 2100 2101 2102 2103 2104 2105 2106 2107 2108 2109 2110 2111 2112 2113 2114 2115 2116 2117 2118 2119 2120 2121 2122 2123 2124 2125 2126 2127 2128 2129 2130 2131 2132 2133 2134 2135 2136 2137 2138 2139 2140 2141 2142 2143 2144 2145 2146 2147 2148 2149 2150 2151 2152 2153 2154 2155 2156 2157 2158 2159 2160 2161 2162 2163 2164 2165 2166 2167 2168 2169 2170 2171 2172 2173 2174 2175 2176 2177 2178 2179 2180 2181 2182 2183 2184 2185 2186 2187 2188 2189 2190 2191 2192 2193 2194 2195 2196 2197 2198 2199 2200 2201 2202 2203 2204 2205 2206 2207 2208 2209 2210 2211 2212 2213 2214 2215 2216 2217 2218 2219 2220 2221 2222 2223 2224 2225 2226 2227 2228 2229 2230 2231 2232 2233 2234 2235 2236 2237 2238 2239 2240 2241 2242 2243 2244 2245 2246 2247 2248 2249 2250 2251 2252 2253 2254 2255 2256 2257 2258 2259 2260 2261 2262 2263 2264 2265 2266 2267 2268 2269 2270 2271 2272 2273 2274 2275 2276 2277 2278 2279 2280 2281 2282 2283 2284 2285 2286 2287 2288 2289 2290 2291 2292 2293 2294 2295 2296 2297 2298 2299 2300 2301 2302 2303 2304 2305 2306 2307 2308 2309 2310 2311 2312 2313 2314 2315 2316 2317 2318 2319 2320 2321 2322 2323 2324 2325 2326 2327 2328 2329 2330 2331 2332 2333 2334 2335 2336 2337 2338 2339 2340 2341 2342 2343 2344 2345 2346 2347 2348 2349 2350 2351 2352 2353 2354 2355 2356 2357 2358 2359 2360 2361 2362 2363 2364 2365 2366 2367 2368 2369 2370 2371 2372 2373 2374 2375 2376 2377 2378 2379 2380 2381 2382 2383 2384 2385 2386 2387 2388 2389 2390 2391 2392 2393 2394 2395 2396 2397 2398 2399 2400 2401 2402 2403 2404 2405 2406 2407 2408 2409 2410 2411 2412 2413 2414 2415 2416 2417 2418 2419 2420 2421 2422 2423 2424 2425 2426 2427 2428 2429 2430 2431 2432 2433 2434 2435 2436 2437 2438 2439 2440 2441 2442 2443 2444 2445 2446 2447 2448 2449 2450 2451 2452 2453 2454 2455 2456 2457 2458 2459 2460 2461 2462 2463 2464 2465 2466 2467 2468 2469 2470 2471 2472 2473 2474 2475 2476 2477 2478 2479 2480 2481 2482 2483 2484 2485 2486 2487 2488 2489 2490 2491 2492 2493 2494 2495 2496 2497 2498 2499 2500 2501 2502 2503 2504 2505 2506 2507 2508 2509 2510 2511 2512 2513 2514 2515 2516 2517 2518 2519 2520 2521 2522 2523 2524 2525 2526 2527 2528 2529 2530 2531 2532 2533 2534 2535 2536 2537 2538 2539 2540 2541 2542 2543 2544 2545 2546 2547 2548 2549 2550 2551 2552 2553 2554 2555 2556 2557 2558 2559 2560 2561 2562 2563 2564 2565 2566 2567 2568 2569 2570 2571 2572 2573 2574 2575 2576 2577 2578 2579 2580 2581 2582 2583 2584 2585 2586 2587 2588 2589 2590 2591 2592 2593 2594 2595 2596 2597 2598 2599 2600 2601 2602 2603 2604 2605 2606 2607 2608 2609 2610 2611 2612 2613 2614 2615 2616 2617 2618 2619 2620 2621 2622 2623 2624 2625 2626 2627 2628 2629 2630 2631 2632 2633 2634 2635 2636 2637 2638 2639 2640 2641 2642 2643 2644 2645 2646 2647 2648 2649 2650 2651 2652 2653 2654 2655 2656 2657 2658 2659 2660 2661 2662 2663 2664 2665 2666 2667 2668 2669 2670 2671 2672 2673 2674 2675 2676 2677 2678 2679 2680 2681 2682 2683 2684 2685 2686 2687 2688 2689 2690 2691 2692 2693 2694 2695 2696 2697 2698 2699 2700 2701 2702 2703 2704 2705 2706 2707 2708 2709 2710 2711 2712 2713 2714 2715 2716 2717 2718 2719 2720 2721 2722 2723 2724 2725 2726 2727 2728 2729 2730 2731 2732 2733 2734 2735 2736 2737 2738 2739 2740 2741 2742 2743 2744 2745 2746 2747 2748 2749 2750 2751 2752 2753 2754 2755 2756 2757 2758 2759 2760 2761 2762 2763 2764 2765 2766 2767 2768 2769 2770 2771 2772 2773 2774 2775 2776 2777 2778 2779 2780 2781 2782 2783 2784 2785 2786 2787 2788 2789 2790 2791 2792 2793 2794 2795 2796 2797 2798 2799 2800 2801 2802 2803 2804 2805 2806 2807 2808 2809 2810 2811 2812 2813 2814 2815 2816 2817 2818 2819 2820 2821 2822 2823 2824 2825 2826 2827 2828 2829 2830 2831 2832 2833 2834 2835 2836 2837 2838 2839 2840 2841 2842 2843 2844 2845 2846 2847 2848 2849 2850 2851 2852 2853 2854 2855 2856 2857 2858 2859 2860 2861 2862 2863 2864 2865 2866 2867 2868 2869 2870 2871 2872 2873 2874 2875 2876 2877 2878 2879 2880 2881 2882 2883 2884 2885 2886 2887 2888 2889 2890 2891 2892 2893 2894 2895 2896 2897 2898 2899 2900 2901 2902 2903 2904 2905 2906 2907 2908 2909 2910 2911 2912 2913 2914 2915 2916 2917 2918 2919 2920 2921 2922 2923 2924 2925 2926 2927 2928 2929 2930 2931 2932 2933 2934 2935 2936 2937 2938 2939 2940 2941 2942 2943 2944 2945 2946 2947 2948 2949 2950 2951 2952 2953 2954 2955 2956 2957 2958 2959 2960 2961 2962 2963 2964 2965 2966 2967 2968 2969 2970 2971 2972 2973 2974 2975 2976 2977 2978 2979 2980 2981 2982 2983 2984 2985 2986 2987 2988 2989 2990 2991 2992 2993 2994 2995 2996 2997 2998 2999 3000 3001 3002 3003 3004 3005 3006 3007 3008 3009 3010 3011 3012 3013 3014 3015 3016 3017 3018 3019 3020 3021 3022 3023 3024 3025 3026 3027 3028 3029 3030 3031 3032 3033 3034 3035 3036 3037 3038 3039 3040 3041 3042 3043 3044 3045 3046 3047 3048 3049 3050 3051 3052 3053 3054 3055 3056 3057 3058 3059 3060 3061 3062 3063 3064 3065 3066 3067 3068 3069 3070 3071 3072 3073 3074 3075 3076 3077 3078 3079 3080 3081 3082 3083 3084 3085 3086 3087 3088 3089 3090 3091 3092 3093 3094 3095 3096 3097 3098 3099 3100 3101 3102 3103 3104 3105 3106 3107 3108 3109 3110 3111 3112 3113 3114 3115 3116 3117 3118 3119 3120 3121 3122 3123 3124 3125 3126 3127 3128 3129 3130 3131 3132 3133 3134 3135 3136 3137 3138 3139 3140 3141 3142 3143 3144 3145 3146 3147 3148 3149 3150 3151 3152 3153 3154 3155 3156 3157 3158 3159 3160 3161 3162 3163 3164 3165 3166 3167 3168 3169 3170 3171 3172 3173 3174 3175 3176 3177 3178 3179 3180 3181 3182 3183 3184 3185 3186 3187 3188 3189 3190 3191 3192 3193 3194 3195 3196 3197 3198 3199 3200 3201 3202 3203 3204 3205 3206 3207 3208 3209 3210 3211 3212 3213 3214 3215 3216 3217 3218 3219 3220 3221 3222 3223 3224 3225 3226 3227 3228 3229 3230 3231 3232 3233 3234 3235 3236 3237 3238 3239 3240 3241 3242 3243 3244 3245 3246 3247 3248 3249 3250 3251 3252 3253 3254 3255 3256 3257 3258 3259 3260 3261 3262 3263 3264 3265 3266 3267 3268 3269 3270 3271 3272 3273 3274 3275 3276 3277 3278 3279 3280 3281 3282 3283 3284 3285 3286 3287 3288 3289 3290 3291 3292 3293 3294 3295 3296 3297 3298 3299 3300 3301 3302 3303 3304 3305 3306 3307 3308 3309 3310 3311 3312 3313 3314 3315 3316 3317 3318 3319 3320 3321 3322 3323 3324 3325 3326 3327 3328 3329 3330 3331 3332 3333 3334 3335 3336 3337 3338 3339 3340 3341 3342 3343 3344 3345 3346 3347 3348 3349 3350 3351 3352 3353 3354 3355 3356 3357 3358 3359 3360 3361 3362 3363 3364 3365 3366 3367 3368 3369 3370 3371 3372 3373 3374 3375 3376 3377 3378 3379 3380 3381 3382 3383 3384 3385 3386 3387 3388 3389 3390 3391 3392 3393 3394 3395 3396 3397 3398 3399 3400 3401 3402 3403 3404 3405 3406 3407 3408 3409 3410 3411 3412 3413 3414 3415 3416 3417 3418 3419 3420 3421 3422 3423 3424 3425 3426 3427 3428 3429 3430 3431 3432 3433 3434 3435 3436 3437 3438 3439 3440 3441 3442 3443 3444 3445 3446 3447 3448 3449 3450 3451 3452 3453 3454 3455 3456 3457 3458 3459 3460 3461 3462 3463 3464 3465 3466 3467 3468 3469 3470 3471 3472 3473 3474 3475 3476 3477 3478 3479 3480 3481 3482 3483 3484 3485 3486 3487 3488 3489 3490 3491 3492 3493 3494 3495 3496 3497 3498 3499 3500 3501 3502 3503 3504 3505 3506 3507 3508 3509 3510 3511 3512 3513 3514 3515 3516 3517 3518 3519 3520 3521 3522 3523 3524 3525 3526 3527 3528 3529 3530 3531 3532 3533 3534 3535 3536 3537 3538 3539 3540 3541 3542 3543 3544 3545 3546 3547 3548 3549 3550 3551 3552 3553 3554 3555 3556 3557 3558 3559 3560
/*! `BitVec` structure This module holds the main working type of the library. Clients can use `BitSlice` directly, but `BitVec` is much more useful for most work. The `BitSlice` module discusses the design decisions for the separation between slice and vector types. !*/ #![cfg(any(feature = "alloc", feature = "std"))] use crate::{ boxed::BitBox, cursor::{ BigEndian, Cursor, }, pointer::BitPtr, slice::BitSlice, store::{ BitIdx, BitStore, }, }; #[cfg(feature = "alloc")] use alloc::{ borrow::{ Borrow, BorrowMut, ToOwned, }, boxed::Box, vec::Vec, }; use core::{ clone::Clone, cmp::{ Eq, Ord, Ordering, PartialEq, PartialOrd, }, convert::{ AsMut, AsRef, From, }, default::Default, fmt::{ self, Debug, Display, Formatter, }, hash::{ Hash, Hasher, }, iter::{ self, DoubleEndedIterator, ExactSizeIterator, Extend, FromIterator, FusedIterator, Iterator, IntoIterator, }, marker::{ PhantomData, Send, Sync, }, mem, ops::{ Add, AddAssign, BitAnd, BitAndAssign, BitOr, BitOrAssign, BitXor, BitXorAssign, Deref, DerefMut, Drop, Index, IndexMut, Range, RangeBounds, RangeFrom, RangeFull, RangeInclusive, RangeTo, RangeToInclusive, Neg, Not, Shl, ShlAssign, Shr, ShrAssign, Sub, SubAssign, }, ptr::{ self, NonNull, }, slice, }; #[cfg(feature = "std")] use std::{ io::{ self, Write, }, }; /** A compact [`Vec`] of bits, whose cursor and storage type can be customized. `BitVec` is a newtype wrapper over `Vec`, and as such is exactly three words in size on the stack. # Examples ```rust use bitvec::prelude::*; let mut bv: BitVec = BitVec::new(); bv.push(false); bv.push(true); assert_eq!(bv.len(), 2); assert_eq!(bv[0], false); assert_eq!(bv.pop(), Some(true)); assert_eq!(bv.len(), 1); bv.set(0, true); assert_eq!(bv[0], true); bv.extend([0u8, 1, 0].iter().map(|n| *n != 0u8)); for bit in &*bv { println!("{}", bit); } assert_eq!(bv, bitvec![1, 0, 1, 0]); ``` The [`bitvec!`] macro is provided to make initialization more convenient. ```rust use bitvec::prelude::*; let mut bv = bitvec![0, 1, 2, 3]; bv.push(false); assert_eq!(bv, bitvec![0, 1, 1, 1, 0]); ``` It can also initialize each element of a `BitVec<_, T>` with a given value. This may be more efficient than performing allocation and initialization in separate steps, especially when initializing a vector of zeros: ```rust use bitvec::prelude::*; let bv = bitvec![0; 15]; assert_eq!(bv, bitvec![0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]); // The following is equivalent, but potentially slower: let mut bv1: BitVec = BitVec::with_capacity(15); bv1.resize(15, false); ``` Use a `BitVec<T>` as an efficient stack: ```rust use bitvec::prelude::*; let mut stack: BitVec = BitVec::new(); stack.push(false); stack.push(true); stack.push(true); while let Some(top) = stack.pop() { // Prints true, true, false println!("{}", top); } ``` # Indexing The `BitVec` type allows you to access values by index, because it implements the [`Index`] trait. An example will be more explicit: ```rust use bitvec::prelude::*; let bv = bitvec![0, 0, 1, 1]; println!("{}", bv[1]); // it will display 'false' ``` However, be careful: if you try to access an index which isn’t in the `BitVec`, your software will panic! You cannot do this: ```rust,should_panic use bitvec::prelude::*; let bv = bitvec![0, 1, 0, 1]; println!("{}", bv[6]); // it will panic! ``` In conclusion: always check if the index you want to get really exists before doing it. # Slicing A `BitVec` is growable. A [`BitSlice`], on the other hand, is fixed size. To get a bit slice, use `&`. Example: ```rust use bitvec::prelude::*; fn read_bitslice(slice: &BitSlice) { // use slice } let bv = bitvec![0, 1]; read_bitslice(&bv); // … and that’s all! // you can also do it like this: let bs : &BitSlice = &bv; ``` In Rust, it’s more common to pass slices as arguments rather than vectors when you do not want to grow or shrink it. The same goes for [`Vec`] and [`&[]`], and [`String`] and [`&str`]. # Capacity and Reallocation The capacity of a bit vector is the amount of space allocated for any future bits that will be added onto the vector. This is not to be confused with the *length* of a vector, which specifies the number of live, useful bits within the vector. If a vector’s length exceeds its capacity, its capacity will automatically be increased, but its storage elements will have to be reallocated. For example, a bit vector with capacity 10 and length 0 would be an allocated, but uninhabited, vector, with space for ten more bits. Pushing ten or fewer bits onto the vector will not change its capacity or cause reallocation to occur. However, if the vector’s length is increased to eleven, it will have to reallocate, which can be slow. For this reason, it is recommended to use [`BitVec::with_capacity`] whenever possible to specify how big the bit vector is expected to get. # Guarantees Due to its incredibly fundamental nature, `BitVec` makes a lot of guarantees about its design. This ensures that it is as low-overhead as possible in the general case, and can be correctly manipulated in fundamental ways by `unsafe` code. Most fundamentally, `BitVec` is and always will be a `([`BitPtr`], capacity)` doublet. No more, no less. The order of these fields is unspecified, and you should **only** interact with the members through the provided APIs. Note that `BitPtr` is ***not directly manipulable***, and must ***never*** be written or interpreted as anything but opaque binary data by user code. When a `BitVec` has allocated memory, then the memory to which it points is on the heap (as defined by the allocator Rust is configured to use by default), and its pointer points to [`len`] initialized bits in order of the [`Cursor`] type parameter, followed by `capacity - len` logically uninitialized bits. `BitVec` will never perform a “small optimization” where elements are stored in its handle representation, for two reasons: - It would make it more difficult for user code to correctly manipulate a `BitVec`. The contents of the `BitVec` would not have a stable address if the handle were moved, and it would be more difficult to determine if a `BitVec` had allocated memory. - It would penalize the general, heap-allocated, case by incurring a branch on every access. `BitVec` will never automatically shrink itself, even if it is emptied. This ensures that no unnecessary allocations or deallocations occur. Emptying a `BitVec` and then refilling it to the same length will incur no calls to the allocator. If you wish to free up unused memory, use [`shrink_to_fit`]. ## Erasure `BitVec` will not specifically overwrite any data that is removed from it, nor will it specifically preserve it. Its uninitialized memory is scratch space that may be used however the implementation desires, and must not be relied upon as stable. Do not rely on removed data to be erased for security purposes. Even if you drop a `BitVec`, its buffer may simply be reused for other data structures in your program. Even if you zero a `BitVec`’s memory first, that may not actually occur if the optimizer does not consider this an observable side effect. There is one case that will never break, however: using `unsafe` to construct a `[T]` slice over the `BitVec`’s capacity, and writing to the excess space, then increasing the length to match, is always valid. # Type Parameters - `C: Cursor`: An implementor of the [`Cursor`] trait. This type is used to convert semantic indices into concrete bit positions in elements, and store or retrieve bit values from the storage type. - `T: BitStore`: An implementor of the [`BitStore`] trait: `u8`, `u16`, `u32`, or `u64` (64-bit systems only). This is the actual type in memory that the vector will use to store data. # Safety The `BitVec` handle has the same *size* as standard Rust `Vec` handles, but it is ***extremely binary incompatible*** with them. Attempting to treat `BitVec<_, T>` as `Vec<T>` in any manner except through the provided APIs is ***catastrophically*** unsafe and unsound. [`BitSlice`]: ../struct.BitSlice.html [`BitVec::with_capacity`]: #method.with_capacity [`BitStore`]: ../trait.BitStore.html [`Cursor`]: ../trait.Cursor.html [`Index`]: https://doc.rust-lang.org/stable/std/ops/trait.Index.html [`String`]: https://doc.rust-lang.org/stable/std/string/struct.String.html [`Vec`]: https://doc.rust-lang.org/stable/std/vec/struct.Vec.html [`bitvec!`]: ../macro.bitvec.html [`clear_on_drop`]: https://docs.rs/clear_on_drop [`len`]: #method.len [`shrink_to_fit`]: #method.shrink_to_fit [`&str`]: https://doc.rust-lang.org/stable/std/primitive.str.html [`&[]`]: https://doc.rust-lang.org/stable/std/primitive.slice.html **/ #[repr(C)] pub struct BitVec<C = BigEndian, T = u8> where C: Cursor, T: BitStore { /// Phantom `Cursor` member to satisfy the constraint checker. _cursor: PhantomData<C>, /// Slice pointer over the owned memory. pointer: BitPtr<T>, /// The number of *elements* this vector has allocated. capacity: usize, } impl<C, T> BitVec<C, T> where C: Cursor, T: BitStore { /// Constructs a new, empty, `BitVec<C, T>`. /// /// The vector does not allocate until bits are written into it. /// /// # Returns /// /// An empty, unallocated, `BitVec` handle. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv: BitVec = BitVec::new(); /// assert!(bv.is_empty()); /// assert_eq!(bv.capacity(), 0); /// ``` pub fn new() -> Self { Self { _cursor: PhantomData, pointer: BitPtr::empty(), capacity: 0, } } /// Constructs a new, empty, `BitVec<T>` with the specified capacity. /// /// The new vector will be able to hold at least `capacity` elements before /// it reallocates. If `capacity` is `0`, it will not allocate. /// /// # Parameters /// /// - `capacity`: The minimum number of bits that the new vector will need /// to be able to hold. /// /// # Returns /// /// An empty vector with at least the given capacity. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv: BitVec = BitVec::with_capacity(10); /// assert!(bv.is_empty()); /// assert!(bv.capacity() >= 10); /// ``` pub fn with_capacity(capacity: usize) -> Self { // Find the number of elements needed to store the requested capacity // of bits. let (cap, _) = BitIdx::from(0).span::<T>(capacity); // Acquire a region of memory large enough for that element number. let (ptr, cap) = { let v = Vec::with_capacity(cap); let (ptr, cap) = (v.as_ptr(), v.capacity()); mem::forget(v); (ptr, cap) }; // Take ownership of that region as an owned BitPtr Self { _cursor: PhantomData, pointer: BitPtr::uninhabited(ptr), capacity: cap, } } /// Constructs a `BitVec` from a single element. /// /// The produced `BitVec` will span the element, and include all bits in it. /// /// # Parameters /// /// - `elt`: The source element. /// /// # Returns /// /// A `BitVec` over the provided element. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = BitVec::<BigEndian, u8>::from_element(5); /// assert_eq!(bv.count_ones(), 2); /// ``` pub fn from_element(elt: T) -> Self { Self::from_vec({ let mut v = Vec::with_capacity(1); v.push(elt); v }) } /// Constructs a `BitVec` from a slice of elements. /// /// The produced `BitVec` will span the provided slice. /// /// # Parameters /// /// - `slice`: The source elements to copy into the new `BitVec`. /// /// # Returns /// /// A `BitVec` set to the provided slice values. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let src = [5, 10]; /// let bv = BitVec::<BigEndian, u8>::from_slice(&src[..]); /// assert!(bv[5]); /// assert!(bv[7]); /// assert!(bv[12]); /// assert!(bv[14]); /// ``` pub fn from_slice(slice: &[T]) -> Self { BitSlice::<C, T>::from_slice(slice).to_owned() } /// Consumes a `Vec<T>` and creates a `BitVec<C, T>` from it. /// /// # Parameters /// /// - `vec`: The source vector whose memory will be used. /// /// # Returns /// /// A new `BitVec` using the `vec` `Vec`’s memory. /// /// # Panics /// /// Panics if the source vector would cause the `BitVec` to overflow /// capacity. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = BitVec::<BigEndian, u8>::from_vec(vec![1, 2, 4, 8]); /// assert_eq!( /// "[00000001, 00000010, 00000100, 00001000]", /// &format!("{}", bv), /// ); /// ``` pub fn from_vec(vec: Vec<T>) -> Self { let len = vec.len(); assert!( len <= BitPtr::<T>::MAX_ELTS, "Vector length {} overflows {}", len, BitPtr::<T>::MAX_ELTS, ); let bs = BitSlice::<C, T>::from_slice(&vec[..]); let pointer = bs.bitptr(); let capacity = vec.capacity(); mem::forget(vec); Self { _cursor: PhantomData, pointer, capacity, } } /// Clones a `&BitSlice` into a `BitVec`. /// /// # Parameters /// /// - `slice` /// /// # Returns /// /// A `BitVec` containing the same bits as the source slice. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bs = [0u8, !0].as_bitslice::<BigEndian>(); /// let bv = BitVec::from_bitslice(bs); /// assert_eq!(bv.len(), 16); /// assert!(bv.some()); /// ``` pub fn from_bitslice(slice: &BitSlice<C, T>) -> Self { Self::from_iter(slice.iter()) } /// Converts a frozen `BitBox` allocation into a growable `BitVec`. /// /// This does not copy or reallocate. /// /// # Parameters /// /// - `slice`: A `BitBox` to be thawed. /// /// # Returns /// /// A growable collection over the original memory of the slice. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = BitVec::from_boxed_bitslice(bitbox![0, 1]); /// assert_eq!(bv.len(), 2); /// assert!(bv.some()); /// ``` pub fn from_boxed_bitslice(slice: BitBox<C, T>) -> Self { let bitptr = slice.bitptr(); mem::forget(slice); unsafe { Self::from_raw_parts(bitptr, bitptr.elements()) } } /// Creates a new `BitVec<C, T>` directly from the raw parts of another. /// /// # Parameters /// /// - `pointer`: The `BitPtr<T>` to use. /// - `capacity`: The number of `T` elements *allocated* in that slab. /// /// # Returns /// /// A `BitVec` over the given slab of memory. /// /// # Safety /// /// This is ***highly*** unsafe, due to the number of invariants that aren’t /// checked: /// /// - `pointer` needs to have been previously allocated by some allocating /// type. /// - `pointer`’s `T` needs to have the same size ***and alignment*** as it /// was initially allocated. /// - `pointer`’s element count needs to be less than or equal to the /// original allocation capacity. /// - `capacity` needs to be the original allocation capacity for the /// vector. This is *not* the value produced by `.capacity()`. /// /// Violating these ***will*** cause problems, like corrupting the handle’s /// concept of memory, the allocator’s internal data structures, and the /// sanity of your program. It is ***absolutely*** not safe to construct a /// `BitVec` whose `T` differs from the type used for the initial /// allocation. /// /// The ownership of `pointer` is effectively transferred to the /// `BitVec<C, T>` which may then deallocate, reallocate, or modify the /// contents of the referent slice at will. Ensure that nothing else uses /// the pointer after calling this function. pub unsafe fn from_raw_parts(pointer: BitPtr<T>, capacity: usize) -> Self { Self { _cursor: PhantomData, pointer, capacity, } } /// Returns the number of bits the vector can hold without reallocating. /// /// # Parameters /// /// - `&self` /// /// # Returns /// /// The number of bits that the vector can hold before reallocating. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv: BitVec = BitVec::with_capacity(10); /// assert!(bv.is_empty()); /// assert!(bv.capacity() >= 10); /// ``` pub fn capacity(&self) -> usize { self.capacity .checked_mul(T::BITS as usize) .expect("Vector capacity overflow") } /// Reserves capacity for at least `additional` more bits to be inserted. /// /// The collection may reserve more space to avoid frequent reallocations. /// After calling `reserve`, capacity will be greater than or equal to /// `self.len() + additional`. Does nothing if the capacity is already /// sufficient. /// /// # Parameters /// /// - `&mut self` /// - `additional`: The number of extra bits to be granted space. /// /// # Panics /// /// Panics if the new capacity would overflow the vector’s limits. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![1; 5]; /// assert!(bv.capacity() >= 5); /// bv.reserve(10); /// assert!(bv.capacity() >= 15); /// ``` pub fn reserve(&mut self, additional: usize) { let newlen = self.len() + additional; assert!( newlen <= BitPtr::<T>::MAX_BITS, "Capacity overflow: {} exceeds {}", newlen, BitPtr::<T>::MAX_BITS, ); // Compute the number of additional elements needed to store the // requested number of additional bits. let (e, _) = self.pointer.tail().span::<T>(additional); self.do_unto_vec(|v| v.reserve(e)); } /// Reserves the minimum capacity for at least `additional` more bits. /// /// After calling `reserve_exact`, the capacity will be greater than or /// equal to `self.len() + additional`. Does nothing if the capacity is /// already sufficient. /// /// Note that the allocator may give the collection more space than it /// requests. Therefore, the capacity cannot be relied upon to be precisely /// minimal. Prefer `reserve` if future insertions are expected. /// /// # Parameters /// /// - `&mut self` /// - `additional`: The number of extra bits to be granted space. /// /// # Panics /// /// Panics if the new capacity would overflow the vector’s limits. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![1; 5]; /// assert!(bv.capacity() >= 5); /// bv.reserve_exact(10); /// assert!(bv.capacity() >= 15); /// ``` pub fn reserve_exact(&mut self, additional: usize) { let newlen = self.len() + additional; assert!( newlen <= BitPtr::<T>::MAX_BITS, "Capacity overflow: {} exceeds {}", newlen, BitPtr::<T>::MAX_BITS, ); // Compute the number of additional elements needed to store the // requested number of additional bits. let (e, _) = self.pointer.tail().span::<T>(additional); self.do_unto_vec(|v| v.reserve_exact(e)); } /// Shrinks the capacity of the vector as much as possible. /// /// It will drop down as close as possible to the length, but the allocator /// may still inform the vector that there is space for bits. /// /// This does not modify the contents of the memory store! It will not zero /// any memory that had been used and then removed from the vector’s live /// count. /// /// # Parameters /// /// - `&mut self` /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![1; 100]; /// let cap = bv.capacity(); /// bv.truncate(10); /// bv.shrink_to_fit(); /// assert!(bv.capacity() <= cap); /// ``` pub fn shrink_to_fit(&mut self) { self.do_unto_vec(Vec::shrink_to_fit); } /// Shortens the vector, keeping the first `len` bits and dropping the rest. /// /// If `len` is greater than the vector’s current length, this has no /// effect. /// /// # Parameters /// /// - `&mut self` /// - `len`: The new length of the vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![1; 15]; /// bv.truncate(10); /// assert_eq!(bv.len(), 10); /// /// bv.truncate(15); /// assert_eq!(bv.len(), 10); /// ``` pub fn truncate(&mut self, len: usize) { if len < self.len() { unsafe { self.bitptr_mut().set_len(len); } } } /// Produces a `BitSlice` containing the entire vector. /// /// Equivalent to `&s[..]`. /// /// # Parameters /// /// - `&self` /// /// # Returns /// /// A `BitSlice` over the vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![0, 1, 1, 0]; /// let bs = bv.as_bitslice(); /// ``` pub fn as_bitslice(&self) -> &BitSlice<C, T> { self.pointer.into_bitslice() } /// Produces a mutable `BitSlice` containing the entire vector. /// /// Equivalent to `&mut s[..]`. /// /// # Parameters /// /// - `&mut self` /// /// # Returns /// /// A mutable `BitSlice` over the vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![0, 1, 1, 0]; /// let bs = bv.as_mut_bitslice(); /// ``` pub fn as_mut_bitslice(&mut self) -> &mut BitSlice<C, T> { self.pointer.into_bitslice_mut() } /// Sets the length of the vector. /// /// This unconditionally sets the size of the vector, without modifying its /// contents. It is up to the caller to ensure that the vector’s buffer can /// hold the new size. /// /// # Parameters /// /// - `&mut self` /// - `len`: The new length of the vector. This must be less than the /// maximum number of bits that the vector can hold. /// /// # Panics /// /// This panics if `len` overflows the vector's intrinsic *or allocated* /// capacities. /// /// # Safety /// /// The caller must ensure that the new length is sound for the vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv: BitVec = BitVec::with_capacity(15); /// assert!(bv.is_empty()); /// unsafe { bv.set_len(10) }; /// assert_eq!(bv.len(), 10); /// ``` pub unsafe fn set_len(&mut self, len: usize) { assert!( len <= BitPtr::<T>::MAX_BITS, "Capacity overflow: {} overflows maximum length {}", len, BitPtr::<T>::MAX_BITS, ); assert!( len <= self.capacity(), "Capacity overflow: {} overflows allocation size {}", len, self.capacity(), ); self.bitptr_mut().set_len(len); } /// Removes a bit from the vector and returns it. /// /// The removed bit is replaced by the last bit in the vector. /// /// # Parameters /// /// - `&mut self` /// - `index`: The index whose bit is to be returned, and replaced by the /// tail. /// /// # Returns /// /// The bit at the requested index. /// /// # Panics /// /// Panics if the index is out of bounds. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![0, 0, 0, 0, 1]; /// assert!(!bv[2]); /// assert_eq!(bv.len(), 5); /// assert!(!bv.swap_remove(2)); /// assert!(bv[2]); /// assert_eq!(bv.len(), 4); /// ``` pub fn swap_remove(&mut self, index: usize) -> bool { let len = self.len(); assert!(index < len, "Index {} out of bounds: {}", index, len); self.swap(index, len - 1); self.pop() .expect("BitVec::swap_remove cannot fail after index validation") } /// Inserts a bit at a position, shifting all bits after it to the right. /// /// Note that this is `O(n)` runtime. /// /// # Parameters /// /// - `&mut self` /// - `index`: The position at which to insert. This may be any value from /// `0` up to *and including* `self.len()`. At `self.len()`, it is /// equivalent to calling `self.push(value)`. /// - `value`: The bit to be inserted. /// /// # Panics /// /// Panics if `index` is greater than the length. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![0, 0, 0, 0]; /// bv.insert(2, true); /// assert_eq!(bv, bitvec![0, 0, 1, 0, 0]); /// bv.insert(5, true); /// assert_eq!(bv, bitvec![0, 0, 1, 0, 0, 1]); /// ``` pub fn insert(&mut self, index: usize, value: bool) { let len = self.len(); assert!(index <= len, "Index {} is out of bounds: {}", index, len); self.push(value); self[index ..].rotate_right(1); } /// Removes and returns the bit at position `index`, shifting all bits after /// it to the left. /// /// # Parameters /// /// - `&mut self` /// - `index`: The position whose bit is to be removed. This must be in the /// domain `0 .. self.len()`. /// /// # Returns /// /// The bit at the requested index. /// /// # Panics /// /// Panics if `index` is out of bounds for the vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![0, 0, 1, 0, 0]; /// assert!(bv.remove(2)); /// assert_eq!(bv, bitvec![0, 0, 0, 0]); /// ``` pub fn remove(&mut self, index: usize) -> bool { let len = self.len(); assert!(index < len, "Index {} is out of bounds: {}", index, len); self[index ..].rotate_left(1); self.pop() .expect("BitVec::remove cannot fail after index validation") } /// Retains only the bits that pass the predicate. /// /// This removes all bits `b` where `f(e)` returns `false`. This method /// operates in place and preserves the order of the retained bits. Because /// it is in-place, it operates in `O(n²)` time. /// /// # Parameters /// /// - `&mut self` /// - `pred`: The testing predicate for each bit. /// /// # Type Parameters /// /// - `F: FnMut(usize, bool) -> bool`: A function that can be invoked on /// each bit, returning whether the bit should be kept or not. Receives /// the index (following [`BitSlice::for_each`]) to provide additional /// context to determine whether the entry satisfies the condition. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![0, 1, 0, 1, 0, 1]; /// bv.retain(|_, b| b); /// assert_eq!(bv, bitvec![1, 1, 1]); /// ``` /// /// [`BitSlice::for_each`]: ../slice/struct.BitSlice.html#method.for_each pub fn retain<F>(&mut self, mut pred: F) where F: FnMut(usize, bool) -> bool { for n in (0 .. self.len()).rev() { if !pred(n, self[n]) { self.remove(n); } } } /// Appends a bit to the back of the vector. /// /// If the vector is at capacity, this may cause a reallocation. /// /// # Parameters /// /// - `&mut self` /// - `value`: The bit value to append. /// /// # Panics /// /// This will panic if the push will cause the vector to allocate above /// `BitPtr<T>` or machine capacity. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv: BitVec = BitVec::new(); /// assert!(bv.is_empty()); /// bv.push(true); /// assert_eq!(bv.len(), 1); /// assert!(bv[0]); /// ``` pub fn push(&mut self, value: bool) { let len = self.len(); assert!( len <= BitPtr::<T>::MAX_BITS, "Capacity overflow: {} >= {}", len, BitPtr::<T>::MAX_BITS, ); // If self is empty *or* tail is at the back edge of an element, push // an element onto the vector. if self.is_empty() || *self.pointer.tail() == T::BITS { self.do_unto_vec(|v| v.push(0.into())); } // At this point, it is always safe to increment the tail, and then // write to the newly live bit. unsafe { self.bitptr_mut().incr_tail() }; self.set(len, value); } /// Removes the last bit from the collection, if present. /// /// # Parameters /// /// - `&mut self` /// /// # Returns /// /// If the vector is not empty, this returns the last bit; if it is empty, /// this returns `None`. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv: BitVec = BitVec::new(); /// assert!(bv.is_empty()); /// bv.push(true); /// assert_eq!(bv.len(), 1); /// assert!(bv[0]); /// /// assert!(bv.pop().unwrap()); /// assert!(bv.is_empty()); /// assert!(bv.pop().is_none()); /// ``` pub fn pop(&mut self) -> Option<bool> { if self.is_empty() { return None; } let out = self[self.len() - 1]; unsafe { self.bitptr_mut().decr_tail() }; Some(out) } /// Moves all the elements of `other` into `self`, leaving `other` empty. /// /// # Parameters /// /// - `&mut self` /// - `other`: A `BitVec` of any order and storage type. Its bits are /// appended to `self`. /// /// # Panics /// /// Panics if the joined vector is too large. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv1 = bitvec![0; 10]; /// let mut bv2 = bitvec![1; 10]; /// bv1.append(&mut bv2); /// assert_eq!(bv1.len(), 20); /// assert!(bv1[10]); /// assert!(bv2.is_empty()); /// ``` pub fn append<D, U>(&mut self, other: &mut BitVec<D, U>) where D: Cursor, U: BitStore { self.extend(other.iter()); other.clear(); } /// Creates a draining iterator that removes the specified range from the /// vector and yields the removed bits. /// /// # Notes /// /// 1. The element range is removed, regardless of whether the iterator is /// consumed. /// 2. The amount of items removed from the vector if the draining iterator /// is leaked, is left unspecified. /// /// # Parameters /// /// - `&mut self` /// - `range`: any range literal, which is used to define the range of the /// vector that is drained. /// /// # Returns /// /// An iterator over the specified range. /// /// # Panics /// /// Panics if the range is ill-formed, or if it is beyond the vector bounds. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![0, 0, 1, 1, 1, 0, 0]; /// assert_eq!(bv.len(), 7); /// for bit in bv.drain(2 .. 5) { /// assert!(bit); /// } /// assert!(bv.not_any()); /// assert_eq!(bv.len(), 4); /// ``` pub fn drain<R>(&mut self, range: R) -> Drain<C, T> where R: RangeBounds<usize> { use core::ops::Bound::*; let len = self.len(); let from = match range.start_bound() { Included(&n) => n, Excluded(&n) => n + 1, Unbounded => 0, }; // First index beyond the end of the drain. let upto = match range.end_bound() { Included(&n) => n + 1, Excluded(&n) => n, Unbounded => len, }; assert!(from <= upto, "The drain start must be below the drain end"); assert!(upto <= len, "The drain end must be within the vector bounds"); unsafe { let ranging: &BitSlice<C, T> = self .as_bitslice()[from .. upto] // remove the lifetime and borrow awareness .bitptr() .into_bitslice(); self.set_len(from); Drain { bitvec: NonNull::from(self), iter: ranging.iter(), tail_start: upto, tail_len: len - upto, } } } /// Clears the vector, removing all values. /// /// Note that this method has no effect on the allocated capacity of the /// vector. /// /// # Parameters /// /// - `&mut self` /// /// # Effects /// /// Becomes an uninhabited slice. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![1; 30]; /// assert_eq!(bv.len(), 30); /// assert!(bv.iter().all(|b| b)); /// bv.clear(); /// assert!(bv.is_empty()); /// ``` /// /// After calling `clear()`, `bv` will no longer show raw memory, so the /// above test cannot show that the underlying memory is not altered. This /// is also an implementation detail on which you should not rely. pub fn clear(&mut self) { unsafe { self.set_len(0) } } /// Splits the collection into two at the given index. /// /// Returns a newly allocated `Self`. `self` contains elements `[0, at)`, /// and the returned `Self` contains elements `[at, self.len())`. /// /// Note that the capacity of `self` does not change. /// /// # Parameters /// /// - `&mut self` /// - `at`: The index at which to perform the split. This must be in the /// domain `0 ..= self.len()`. When it is `self.len()`, an empty vector is /// returned. /// /// # Returns /// /// A new `BitVec` containing all the elements from `at` onwards. /// /// # Panics /// /// Panics if `at` is beyond `self.len()`. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv1 = bitvec![0, 0, 0, 1, 1, 1]; /// let bv2 = bv1.split_off(3); /// assert_eq!(bv1, bitvec![0, 0, 0]); /// assert_eq!(bv2, bitvec![1, 1, 1]); /// ``` pub fn split_off(&mut self, at: usize) -> Self { let len = self.len(); assert!(at <= len, "Index out of bounds: {} is beyond {}", at, len); match at { 0 => unsafe { let out = Self::from_raw_parts(self.pointer, self.capacity); ptr::write(self, Self::new()); out }, n if n == len => Self::new(), _ => { let out = self.as_bitslice().iter().skip(at).collect(); self.truncate(at); out }, } } /// Resizes the `BitVec` in place so that `len` is equal to `new_len`. /// /// If `new_len` is greater than `len`, then the vector is extended by the /// difference, and filled with the provided value. If `new_len` is less /// than `len`, then the vector is just truncated. /// /// # Parameters /// /// - `&mut self` /// - `new_len`: The new length of the vector. /// - `value`: The fill value if the vector is to be extended. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![0; 4]; /// bv.resize(8, true); /// assert_eq!(bv, bitvec![0, 0, 0, 0, 1, 1, 1, 1]); /// bv.resize(5, false); /// assert_eq!(bv, bitvec![0, 0, 0, 0, 1]); /// ``` pub fn resize(&mut self, new_len: usize, value: bool) { let len = self.len(); if new_len < len { self.truncate(new_len); } else if new_len > len { self.extend(iter::repeat(value).take(new_len - len)); } } /// Creates a splicing iterator that exchanges the specified range for the /// `replacement` iterator, yielding the removed items. The range and its /// replacement do not need to be the same size. /// /// # Notes /// /// 1. The element range is removed and replaced even if the iterator /// produced by this method is not fully consumed. /// 2. It is unspecified how many bits are removed from the `BitVec` if the /// returned iterator is leaked. /// 3. The input iterator `replacement` is only consumed when the returned /// iterator is dropped. /// 4. This is optimal if: /// - the tail (elements in the `BitVec` after `range`) is empty, /// - `replace_with` yields fewer characters than `range`’s length, /// - the lower bound of `replacement.size_hint()` is exact. /// /// # Parameters /// /// - `&mut self` /// - `range`: A range of indices in the `BitVec` to pull out of the /// collection. /// - `replacement`: Something which can be used to provide new bits to /// replace the removed range. /// /// The entirety of `replacement` will be inserted into the slot marked by /// `range`. If `replacement` is an infinite iterator, then this will hang, /// and crash your program. /// /// # Returns /// /// An iterator over the bits marked by `range`. /// /// # Panics /// /// Panics if the range is ill-formed, or extends past the end of the /// `BitVec`. /// /// # Examples /// /// This example starts with six bits of zero, and then splices out bits 2 /// and 3 and replaces them with four bits of one. /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![0; 6]; /// let bv2 = bitvec![1; 4]; /// /// let s = bv.splice(2 .. 4, bv2).collect::<BitVec>(); /// assert_eq!(s.len(), 2); /// assert!(!s[0]); /// assert_eq!(bv, bitvec![0, 0, 1, 1, 1, 1, 0, 0]); /// ``` pub fn splice<R, I>( &mut self, range: R, replacement: I, ) -> Splice<C, T, <I as IntoIterator>::IntoIter> where R: RangeBounds<usize>, I: IntoIterator<Item=bool> { Splice { drain: self.drain(range), splice: replacement.into_iter(), } } /// Sets the backing storage to the provided element. /// /// This unconditionally sets each allocated element in the backing storage /// to the provided value, without altering the `BitVec` length or capacity. /// It operates on the underlying `Vec`’s memory region directly, and will /// ignore the `BitVec`’s cursors. /// /// This has the unobservable effect of setting the allocated, but dead, /// bits beyond the end of the vector’s *length*, up to its *capacity*. /// /// # Parameters /// /// - `&mut self` /// - `element`: The value to which each allocated element in the backing /// store will be set. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![0; 10]; /// assert_eq!(bv.as_slice(), &[0, 0]); /// bv.set_elements(0xA5); /// assert_eq!(bv.as_slice(), &[0xA5, 0xA5]); /// ``` pub fn set_elements(&mut self, element: T) { self.do_unto_vec(|v| { let (ptr, cap) = (v.as_mut_ptr(), v.capacity()); for elt in unsafe { slice::from_raw_parts_mut(ptr, cap) } { *elt = element; } }) } /// Performs “reverse” addition (left to right instead of right to left). /// /// This addition traverses the addends from left to right, performing /// the addition at each index and writing the sum into `self`. /// /// If `addend` expires before `self` does, `addend` is zero-extended and /// the carry propagates through the rest of `self`. If `self` expires /// before `addend`, then `self` is zero-extended and the carry propagates /// through the rest of `addend`, growing `self` until `addend` expires. /// /// An infinite `addend` will cause unbounded memory growth until the vector /// overflows and panics. /// /// # Parameters /// /// - `self` /// - `addend: impl IntoIterator<Item=bool>`: A stream of bits to add into /// `self`, from left to right. /// /// # Returns /// /// The sum vector of `self` and `addend`. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let a = bitvec![0, 1, 0, 1]; /// let b = bitvec![0, 0, 1, 1]; /// let c = a.add_reverse(b); /// assert_eq!(c, bitvec![0, 1, 1, 0, 1]); /// ``` pub fn add_reverse<I>(mut self, addend: I) -> Self where I: IntoIterator<Item=bool> { self.add_assign_reverse(addend); self } /// Performs “reverse” addition (left to right instead of right to left). /// /// This addition traverses the addends from left to right, performing /// the addition at each index and writing the sum into `self`. /// /// If `addend` expires before `self` does, `addend` is zero-extended and /// the carry propagates through the rest of `self`. If `self` expires /// before `addend`, then `self` is zero-extended and the carry propagates /// through the rest of `addend`, growing `self` until `addend` expires. /// /// An infinite `addend` will cause unbounded memory growth until the vector /// overflows and panics. /// /// # Parameters /// /// - `&mut self` /// - `addend: impl IntoIterator<Item=bool>`: A stream of bits to add into /// `self`, from left to right. /// /// # Effects /// /// `self` may grow as a result of the final carry-out bit being `1` and /// pushed onto the right end. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut a = bitvec![0, 1, 0, 1]; /// let b = bitvec![0, 0, 1, 1]; /// a.add_assign_reverse(&b); /// assert_eq!(a, bitvec![0, 1, 1, 0, 1]); /// ``` pub fn add_assign_reverse<I>(&mut self, addend: I) where I: IntoIterator<Item=bool> { // Set up iteration over the addend let mut addend = addend.into_iter().fuse(); // Delegate to the `BitSlice` implementation for the initial addition. // If `addend` expires first, it zero-extends; if `self` expires first, // `addend` will still have its remnant for the next stage. let mut c = self.as_mut_bitslice().add_assign_reverse(addend.by_ref()); // If `addend` still has bits to provide, zero-extend `self` and add // them in. for b in addend { let (y, z) = crate::rca1(false, b, c); self.push(y); c = z; } if c { self.push(true); } } /// Changes the cursor type on the vector handle, without changing its /// contents. /// /// # Parameters /// /// - `self` /// /// # Returns /// /// An equivalent vector handle with a new cursor type. The contents of the /// backing storage are unchanged. /// /// To reorder the bits in memory, drain this vector into a new handle with /// the desired cursor type. pub fn change_cursor<D>(self) -> BitVec<D, T> where D: Cursor { let (bp, cap) = (self.pointer, self.capacity); mem::forget(self); unsafe { BitVec::from_raw_parts(bp, cap) } } /// Degrades a `BitVec` to a `BitBox`, freezing its size. /// /// # Parameters /// /// - `self` /// /// # Returns /// /// Itself, with its size frozen and ungrowable. pub fn into_boxed_bitslice(self) -> BitBox<C, T> { let pointer = self.pointer; // Convert the Vec allocation into a Box<[T]> allocation mem::forget(self.into_boxed_slice()); unsafe { BitBox::from_raw(pointer) } } /// Degrades a `BitVec` to a standard boxed slice. /// /// # Parameters /// /// - `self` /// /// # Returns /// /// A boxed slice of the data the `BitVec` had owned. pub fn into_boxed_slice(self) -> Box<[T]> { self.into_vec().into_boxed_slice() } /// Degrades a `BitVec` to a standard `Vec`. /// /// # Parameters /// /// - `self` /// /// # Returns /// /// The plain vector underlying the `BitVec`. pub fn into_vec(self) -> Vec<T> { let slice = self.pointer.as_mut_slice(); let out = unsafe { Vec::from_raw_parts(slice.as_mut_ptr(), slice.len(), self.capacity) }; mem::forget(self); out } /// Gets the raw `BitPtr` powering the vector. /// /// # Parameters /// /// - `&self` /// /// # Returns /// /// The underlying `BitPtr` for the vector. /// /// # Notes /// /// The `BitPtr<T>` return type is opaque, and not exported by the crate. /// Users are not able to use it in any way except to construct another /// `BitVec<_, T>` from it. It is not possible for user code to even express /// the name of the type. /// /// ```rust /// use bitvec::prelude::*; /// use std::mem; /// /// let bv = bitvec![1; 10]; /// let bitptr = bv.bitptr(); /// let cap = bv.capacity(); /// mem::forget(bv); /// let bv2 = unsafe { /// BitVec::<BigEndian, _>::from_raw_parts(bitptr, cap) /// }; /// assert_eq!(bv2.len(), 10); /// assert!(bv2[9]); /// ``` pub fn bitptr(&self) -> BitPtr<T> { self.pointer } /// Gives write access to the `BitPtr` structure powering the vector. /// /// # Parameters /// /// - `&mut self` /// /// # Returns /// /// A mutable reference to the interior `BitPtr`. pub(crate) fn bitptr_mut(&mut self) -> &mut BitPtr<T> { &mut self.pointer } /// Permits a function to modify the `Vec<T>` underneath a `BitVec<_, T>`. /// /// This produces a `Vec<T>` structure referring to the same data region as /// the `BitVec<_, T>`, allows a function to mutably view it, and then /// forgets the `Vec<T>` after the function concludes. /// /// # Parameters /// /// - `&mut self` /// - `func`: A function which receives a mutable borrow to the `Vec<T>` /// underlying the `BitVec<_, T>`. /// /// # Type Parameters /// /// - `F: FnOnce(&mut Vec<T>) -> R`: Any callable object (function or /// closure) which receives a mutable borrow of a `Vec<T>`. /// /// - `R`: The return value from the called function or closure. fn do_unto_vec<F, R>(&mut self, func: F) -> R where F: FnOnce(&mut Vec<T>) -> R { let slice = self.pointer.as_mut_slice(); let mut v = unsafe { Vec::from_raw_parts(slice.as_mut_ptr(), slice.len(), self.capacity) }; let out = func(&mut v); // The only change is that the pointer might relocate. The region data // will remain untouched. Vec guarantees it will never produce an // invalid pointer. unsafe { self.bitptr_mut().set_pointer(v.as_ptr()); } // self.pointer = unsafe { BitPtr::new_unchecked(v.as_ptr(), e, h, t) }; self.capacity = v.capacity(); mem::forget(v); out } /// Permits a function to view the `Vec<T>` underneath a `BitVec<_, T>`. /// /// This produces a `Vec<T>` structure referring to the same data region as /// the `BitVec<_, T>`, allows a function to immutably view it, and then /// forgets the `Vec<T>` after the function concludes. /// /// # Parameters /// /// - `&self` /// - `func`: A function which receives an immutable borrow to the `Vec<T>` /// underlying the `BitVec<_, T>`. /// /// # Returns /// /// The return value of `func`. /// /// # Type Parameters /// /// - `F: FnOnce(&Vec<T>)`: Any callable object (function or closure) which /// receives an immutable borrow of a `Vec<T>` and returns nothing. /// /// # Safety /// /// This produces an empty `Vec<T>` if the `BitVec<_, T>` is empty. fn do_with_vec<F, R>(&self, func: F) -> R where F: FnOnce(&Vec<T>) -> R { let slice = self.pointer.as_mut_slice(); let v: Vec<T> = unsafe { Vec::from_raw_parts(slice.as_mut_ptr(), slice.len(), self.capacity) }; let out = func(&v); mem::forget(v); out } } /// Signifies that `BitSlice` is the borrowed form of `BitVec`. impl<C, T> Borrow<BitSlice<C, T>> for BitVec<C, T> where C: Cursor, T: BitStore { /// Borrows the `BitVec` as a `BitSlice`. /// /// # Parameters /// /// - `&self` /// /// # Returns /// /// A borrowed `BitSlice` of the vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// use std::borrow::Borrow; /// /// let bv = bitvec![0; 13]; /// let bs: &BitSlice = bv.borrow(); /// assert!(!bs[10]); /// ``` fn borrow(&self) -> &BitSlice<C, T> { self.as_bitslice() } } /// Signifies that `BitSlice` is the borrowed form of `BitVec`. impl<C, T> BorrowMut<BitSlice<C, T>> for BitVec<C, T> where C: Cursor, T: BitStore { /// Mutably borrows the `BitVec` as a `BitSlice`. /// /// # Parameters /// /// - `&mut self` /// /// # Returns /// /// A mutably borrowed `BitSlice` of the vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// use std::borrow::BorrowMut; /// /// let mut bv = bitvec![0; 13]; /// let bs: &mut BitSlice = bv.borrow_mut(); /// assert!(!bs[10]); /// bs.set(10, true); /// assert!(bs[10]); /// ``` fn borrow_mut(&mut self) -> &mut BitSlice<C, T> { self.as_mut_bitslice() } } impl<C, T> Clone for BitVec<C, T> where C: Cursor, T: BitStore { fn clone(&self) -> Self { let new_vec = self.do_with_vec(Clone::clone); let capacity = new_vec.capacity(); let mut pointer = self.pointer; unsafe { pointer.set_pointer(new_vec.as_ptr()); } mem::forget(new_vec); Self { _cursor: PhantomData, pointer, // unsafe { BitPtr::new_unchecked(ptr, e, h, t) }, capacity, } } fn clone_from(&mut self, other: &Self) { let slice = other.pointer.as_slice(); self.clear(); // Copy the other data region into the underlying vector, then grab its // pointer and capacity values. let (ptr, capacity) = self.do_unto_vec(|v| { v.copy_from_slice(slice); (v.as_ptr(), v.capacity()) }); // Copy the other `BitPtr<T>`, let mut pointer = other.pointer; // Then set it to aim at the copied pointer. unsafe { pointer.set_pointer(ptr); } // And set the new pointer/capacity. self.pointer = pointer; self.capacity = capacity; } } impl<C, T> Eq for BitVec<C, T> where C: Cursor, T: BitStore {} impl<C, T> Ord for BitVec<C, T> where C: Cursor, T: BitStore { fn cmp(&self, rhs: &Self) -> Ordering { self.as_bitslice().cmp(rhs.as_bitslice()) } } /// Tests if two `BitVec`s are semantically — not bitwise — equal. /// /// It is valid to compare two vectors of different cursor or element types. /// /// The equality condition requires that they have the same number of stored /// bits and that each pair of bits in semantic order are identical. impl<A, B, C, D> PartialEq<BitVec<C, D>> for BitVec<A, B> where A: Cursor, B: BitStore, C: Cursor, D: BitStore { /// Performs a comparison by `==`. /// /// # Parameters /// /// - `&self` /// - `rhs`: The other vector to compare. /// /// # Returns /// /// Whether the vectors compare equal. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let l: BitVec<LittleEndian, u16> = bitvec![LittleEndian, u16; 0, 1, 0, 1]; /// let r: BitVec<BigEndian, u32> = bitvec![BigEndian, u32; 0, 1, 0, 1]; /// assert!(l == r); /// ``` /// /// This example uses the same types to prove that raw, bitwise, values are /// not used for equality comparison. /// /// ```rust /// use bitvec::prelude::*; /// /// let l: BitVec<BigEndian, u8> = bitvec![BigEndian, u8; 0, 1, 0, 1]; /// let r: BitVec<LittleEndian, u8> = bitvec![LittleEndian, u8; 0, 1, 0, 1]; /// /// assert_eq!(l, r); /// assert_ne!(l.as_slice(), r.as_slice()); /// ``` fn eq(&self, rhs: &BitVec<C, D>) -> bool { self.as_bitslice().eq(rhs.as_bitslice()) } } impl<A, B, C, D> PartialEq<BitSlice<C, D>> for BitVec<A, B> where A: Cursor, B: BitStore, C: Cursor, D: BitStore { fn eq(&self, rhs: &BitSlice<C, D>) -> bool { self.as_bitslice().eq(rhs) } } impl<A, B, C, D> PartialEq<&BitSlice<C, D>> for BitVec<A, B> where A: Cursor, B: BitStore, C: Cursor, D: BitStore { fn eq(&self, rhs: &&BitSlice<C, D>) -> bool { self.as_bitslice().eq(*rhs) } } /// Compares two `BitVec`s by semantic — not bitwise — ordering. /// /// The comparison sorts by testing each index for one vector to have a set bit /// where the other vector has an unset bit. If the vectors are different, the /// vector with the set bit sorts greater than the vector with the unset bit. /// /// If one of the vectors is exhausted before they differ, the longer vector is /// greater. impl<A, B, C, D> PartialOrd<BitVec<C, D>> for BitVec<A, B> where A: Cursor, B: BitStore, C: Cursor, D: BitStore { /// Performs a comparison by `<` or `>`. /// /// # Parameters /// /// - `&self` /// - `rhs`: The other vector to compare. /// /// # Returns /// /// The relative ordering of the two vectors. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let a = bitvec![0, 1, 0, 0]; /// let b = bitvec![0, 1, 0, 1]; /// let c = bitvec![0, 1, 0, 1, 1]; /// assert!(a < b); /// assert!(b < c); /// ``` fn partial_cmp(&self, rhs: &BitVec<C, D>) -> Option<Ordering> { self.as_bitslice().partial_cmp(rhs.as_bitslice()) } } impl<A, B, C, D> PartialOrd<BitSlice<C, D>> for BitVec<A, B> where A: Cursor, B: BitStore, C: Cursor, D: BitStore { fn partial_cmp(&self, rhs: &BitSlice<C, D>) -> Option<Ordering> { self.as_bitslice().partial_cmp(rhs) } } impl<A, B, C, D> PartialOrd<&BitSlice<C, D>> for BitVec<A, B> where A: Cursor, B: BitStore, C: Cursor, D: BitStore { fn partial_cmp(&self, rhs: &&BitSlice<C, D>) -> Option<Ordering> { self.as_bitslice().partial_cmp(*rhs) } } impl<C, T> AsMut<BitSlice<C, T>> for BitVec<C, T> where C: Cursor, T: BitStore { fn as_mut(&mut self) -> &mut BitSlice<C, T> { self.as_mut_bitslice() } } /// Gives write access to all live elements in the underlying storage, including /// the partially-filled tail. impl<C, T> AsMut<[T]> for BitVec<C, T> where C: Cursor, T: BitStore { fn as_mut(&mut self) -> &mut [T] { self.as_mut_slice() } } impl<C, T> AsRef<BitSlice<C, T>> for BitVec<C, T> where C: Cursor, T: BitStore { fn as_ref(&self) -> &BitSlice<C, T> { self.as_bitslice() } } /// Gives read access to all live elements in the underlying storage, including /// the partially-filled tail. impl<C, T> AsRef<[T]> for BitVec<C, T> where C: Cursor, T: BitStore { /// Accesses the underlying store. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![0, 0, 0, 0, 0, 0, 0, 0, 1]; /// assert_eq!(&[0, 0b1000_0000], bv.as_slice()); /// ``` fn as_ref(&self) -> &[T] { self.as_slice() } } impl<C, T> From<&BitSlice<C, T>> for BitVec<C, T> where C: Cursor, T: BitStore { fn from(src: &BitSlice<C, T>) -> Self { Self::from_bitslice(src) } } /// Builds a `BitVec` out of a slice of `bool`. /// /// This is primarily for the `bitvec!` macro; it is not recommended for general /// use. impl<C, T> From<&[bool]> for BitVec<C, T> where C: Cursor, T: BitStore { fn from(src: &[bool]) -> Self { src.iter().cloned().collect() } } impl<C, T> From<BitBox<C, T>> for BitVec<C, T> where C: Cursor, T: BitStore { fn from(src: BitBox<C, T>) -> Self { Self::from_boxed_bitslice(src) } } impl<C, T> From<&[T]> for BitVec<C, T> where C: Cursor, T: BitStore { fn from(src: &[T]) -> Self { Self::from_slice(src) } } impl<C, T> From<Box<[T]>> for BitVec<C, T> where C: Cursor, T: BitStore { fn from(src: Box<[T]>) -> Self { Self::from_boxed_bitslice(BitBox::from_boxed_slice(src)) } } impl<C, T> Into<Box<[T]>> for BitVec<C, T> where C: Cursor, T: BitStore { fn into(self) -> Box<[T]> { self.into_boxed_slice() } } /// Builds a `BitVec` out of a `Vec` of elements. /// /// This moves the memory as-is from the source buffer into the new `BitVec`. /// The source buffer will be unchanged by this operation, so you don't need to /// worry about using the correct cursor type. impl<C, T> From<Vec<T>> for BitVec<C, T> where C: Cursor, T: BitStore { fn from(src: Vec<T>) -> Self { Self::from_vec(src) } } impl<C, T> Into<Vec<T>> for BitVec<C, T> where C: Cursor, T: BitStore { fn into(self) -> Vec<T> { self.into_vec() } } impl<C, T> Default for BitVec<C, T> where C: Cursor, T: BitStore { fn default() -> Self { Self::new() } } /// Prints the `BitVec` for debugging. /// /// The output is of the form `BitVec<C, T> [ELT, *]`, where `<C, T>` is the /// cursor and element type, with square brackets on each end of the bits and /// all the live elements in the vector printed in binary. The printout is /// always in semantic order, and may not reflect the underlying store. To see /// the underlying store, use `format!("{:?}", self.as_slice());` instead. /// /// The alternate character `{:#?}` prints each element on its own line, rather /// than separated by a space. impl<C, T> Debug for BitVec<C, T> where C: Cursor, T: BitStore { /// Renders the `BitVec` type header and contents for debug. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![LittleEndian, u16; /// 0, 1, 0, 1, 0, 0, 0, 0, 1, 1, 1, 1, 0, 1, 0, 1 /// ]; /// assert_eq!( /// "BitVec<LittleEndian, u16> [0101000011110101]", /// &format!("{:?}", bv) /// ); /// ``` fn fmt(&self, f: &mut Formatter) -> fmt::Result { f.write_str("BitVec<")?; f.write_str(C::TYPENAME)?; f.write_str(", ")?; f.write_str(T::TYPENAME)?; f.write_str("> ")?; Display::fmt(&**self, f) } } /// Prints the `BitVec` for displaying. /// /// This prints each element in turn, formatted in binary in semantic order (so /// the first bit seen is printed first and the last bit seen printed last). /// Each element of storage is separated by a space for ease of reading. /// /// The alternate character `{:#}` prints each element on its own line. /// /// To see the in-memory representation, use `AsRef` to get access to the raw /// elements and print that slice instead. impl<C, T> Display for BitVec<C, T> where C: Cursor, T: BitStore { /// Renders the `BitVec` contents for display. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![BigEndian, u8; 0, 1, 0, 0, 1, 0, 1, 1, 0, 1]; /// assert_eq!("[01001011, 01]", &format!("{}", bv)); /// ``` fn fmt(&self, f: &mut Formatter) -> fmt::Result { Display::fmt(&**self, f) } } /// Writes the contents of the `BitVec`, in semantic bit order, into a hasher. impl<C, T> Hash for BitVec<C, T> where C: Cursor, T: BitStore { /// Writes each bit of the `BitVec`, as a full `bool`, into the hasher. /// /// # Parameters /// /// - `&self` /// - `hasher`: The hashing pool into which the vector is written. fn hash<H: Hasher>(&self, hasher: &mut H) { <BitSlice<C, T> as Hash>::hash(self, hasher) } } #[cfg(feature = "std")] impl<C, T> Write for BitVec<C, T> where C: Cursor, T: BitStore { fn write(&mut self, buf: &[u8]) -> io::Result<usize> { use std::cmp; let amt = cmp::min(buf.len(), BitPtr::<T>::MAX_BITS - self.len()); self.extend(<&BitSlice<C, u8>>::from(buf)); Ok(amt) } fn flush(&mut self) -> io::Result<()> { Ok(()) } } /// Extends a `BitVec` with the contents of another bitstream. /// /// At present, this just calls `.push()` in a loop. When specialization becomes /// available, it will be able to more intelligently perform bulk moves from the /// source into `self` when the source is `BitSlice`-compatible. impl<C, T> Extend<bool> for BitVec<C, T> where C: Cursor, T: BitStore { /// Extends a `BitVec` from another bitstream. /// /// # Parameters /// /// - `&mut self` /// - `src`: A source bitstream. /// /// # Type Parameters /// /// - `I: IntoIterator<Item=bool>`: The source bitstream with which to /// extend `self`. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![0; 4]; /// bv.extend(bitvec![1; 4]); /// assert_eq!(0x0F, bv.as_slice()[0]); /// ``` fn extend<I: IntoIterator<Item=bool>>(&mut self, src: I) { let iter = src.into_iter(); match iter.size_hint() { (_, Some(hi)) => self.reserve(hi), (lo, None) => self.reserve(lo), } iter.for_each(|b| self.push(b)); } } /// Permits the construction of a `BitVec` by using `.collect()` on an iterator /// of `bool`. impl<C, T> FromIterator<bool> for BitVec<C, T> where C: Cursor, T: BitStore { /// Collects an iterator of `bool` into a vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// use std::iter::repeat; /// let bv: BitVec = repeat(true) /// .take(4) /// .chain(repeat(false).take(4)) /// .collect(); /// assert_eq!(bv.as_slice()[0], 0xF0); /// ``` fn from_iter<I: IntoIterator<Item=bool>>(src: I) -> Self { let iter = src.into_iter(); let mut bv = match iter.size_hint() { | (_, Some(len)) | (len, _) => Self::with_capacity(len), }; for bit in iter { bv.push(bit); } bv } } /// Produces an iterator over all the bits in the vector. /// /// This iterator follows the ordering in the vector type, and implements /// `ExactSizeIterator`, since `BitVec`s always know exactly how large they are, /// and `DoubleEndedIterator`, since they have known ends. impl<C, T> IntoIterator for BitVec<C, T> where C: Cursor, T: BitStore { type Item = bool; type IntoIter = IntoIter<C, T>; /// Iterates over the vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![BigEndian, u8; 1, 1, 1, 1, 0, 0, 0, 0]; /// let mut count = 0; /// for bit in bv { /// if bit { count += 1; } /// } /// assert_eq!(count, 4); /// ``` fn into_iter(self) -> Self::IntoIter { IntoIter { region: self.pointer, bitvec: self, } } } impl<'a, C, T> IntoIterator for &'a BitVec<C, T> where C: Cursor, T: 'a + BitStore { type Item = bool; type IntoIter = <&'a BitSlice<C, T> as IntoIterator>::IntoIter; fn into_iter(self) -> Self::IntoIter { <&'a BitSlice<C, T> as IntoIterator>::into_iter(self) } } /// `BitVec` is safe to move across thread boundaries, as is `&mut BitVec`. unsafe impl<C, T> Send for BitVec<C, T> where C: Cursor, T: BitStore {} /// `&BitVec` is safe to move across thread boundaries. unsafe impl<C, T> Sync for BitVec<C, T> where C: Cursor, T: BitStore {} /// Adds two `BitVec`s together, zero-extending the shorter. /// /// `BitVec` addition works just like adding numbers longhand on paper. The /// first bits in the `BitVec` are the highest, so addition works from right to /// left, and the shorter `BitVec` is assumed to be extended to the left with /// zero. /// /// The output `BitVec` may be one bit longer than the longer input, if addition /// overflowed. /// /// Numeric arithmetic is provided on `BitVec` as a convenience. Serious numeric /// computation on variable-length integers should use the `num_bigint` crate /// instead, which is written specifically for that use case. `BitVec`s are not /// intended for arithmetic, and `bitvec` makes no guarantees about sustained /// correctness in arithmetic at this time. impl<C, T> Add for BitVec<C, T> where C: Cursor, T: BitStore { type Output = Self; /// Adds two `BitVec`s. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let a = bitvec![0, 1, 0, 1]; /// let b = bitvec![0, 0, 1, 1]; /// let s = a + b; /// assert_eq!(bitvec![1, 0, 0, 0], s); /// ``` /// /// This example demonstrates the addition of differently-sized `BitVec`s, /// and will overflow. /// /// ```rust /// use bitvec::prelude::*; /// /// let a = bitvec![1; 4]; /// let b = bitvec![1; 1]; /// let s = b + a; /// assert_eq!(bitvec![1, 0, 0, 0, 0], s); /// ``` fn add(mut self, addend: Self) -> Self::Output { self += addend; self } } /// Adds another `BitVec` into `self`, zero-extending the shorter. /// /// `BitVec` addition works just like adding numbers longhand on paper. The /// first bits in the `BitVec` are the highest, so addition works from right to /// left, and the shorter `BitVec` is assumed to be extended to the left with /// zero. /// /// The output `BitVec` may be one bit longer than the longer input, if addition /// overflowed. /// /// Numeric arithmetic is provided on `BitVec` as a convenience. Serious numeric /// computation on variable-length integers should use the `num_bigint` crate /// instead, which is written specifically for that use case. `BitVec`s are not /// intended for arithmetic, and `bitvec` makes no guarantees about sustained /// correctness in arithmetic at this time. impl<C, T> AddAssign for BitVec<C, T> where C: Cursor, T: BitStore { /// Adds another `BitVec` into `self`. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut a = bitvec![1, 0, 0, 1]; /// let b = bitvec![0, 1, 1, 1]; /// a += b; /// assert_eq!(a, bitvec![1, 0, 0, 0, 0]); /// ``` fn add_assign(&mut self, mut addend: Self) { use core::iter::repeat; // If the other vec is longer, swap them before continuing. if addend.len() > self.len() { mem::swap(self, &mut addend); } // Now that self.len() >= addend.len(), proceed with addition. let mut c = false; let mut stack = BitVec::<C, T>::with_capacity(self.len()); let addend = addend.into_iter().rev().chain(repeat(false)); for (a, b) in self.iter().rev().zip(addend) { let (y, z) = crate::rca1(a, b, c); stack.push(y); c = z; } // If the carry made it to the end, push it. if c { stack.push(true); } // Unwind the stack into `self`. self.clear(); self.extend(stack.into_iter().rev()); } } /// Performs the Boolean `AND` operation between each element of a `BitVec` and /// anything that can provide a stream of `bool` values (such as another /// `BitVec`, or any `bool` generator of your choice). The `BitVec` emitted will /// have the length of the shorter sequence of bits -- if one is longer than the /// other, the extra bits will be ignored. impl<C, T, I> BitAnd<I> for BitVec<C, T> where C: Cursor, T: BitStore, I: IntoIterator<Item=bool> { type Output = Self; /// `AND`s a vector and a bitstream, producing a new vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let lhs = bitvec![BigEndian, u8; 0, 1, 0, 1]; /// let rhs = bitvec![BigEndian, u8; 0, 0, 1, 1]; /// let and = lhs & rhs; /// assert_eq!("[0001]", &format!("{}", and)); /// ``` fn bitand(mut self, rhs: I) -> Self::Output { self &= rhs; self } } /// Performs the Boolean `AND` operation in place on a `BitVec`, using a stream /// of `bool` values as the other bit for each operation. If the other stream is /// shorter than `self`, `self` will be truncated when the other stream expires. impl<C, T, I> BitAndAssign<I> for BitVec<C, T> where C: Cursor, T: BitStore, I: IntoIterator<Item=bool> { /// `AND`s another bitstream into a vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut src = bitvec![BigEndian, u8; 0, 1, 0, 1]; /// src &= bitvec![BigEndian, u8; 0, 0, 1, 1]; /// assert_eq!("[0001]", &format!("{}", src)); /// ``` fn bitand_assign(&mut self, rhs: I) { // let mut len = 0; // for (idx, other) in (0 .. self.len()).zip(rhs.into_iter()) { // let val = self[idx] & other; // self.set(idx, val); // len += 1; // } let len = rhs.into_iter() .take(self.len()) .enumerate() .flat_map(|(i, r)| self.get(i).map(|l| self.set(i, l & r))) .count(); self.truncate(len); } } /// Performs the Boolean `OR` operation between each element of a `BitVec` and /// anything that can provide a stream of `bool` values (such as another /// `BitVec`, or any `bool` generator of your choice). The `BitVec` emitted will /// have the length of the shorter sequence of bits -- if one is longer than the /// other, the extra bits will be ignored. impl<C, T, I> BitOr<I> for BitVec<C, T> where C: Cursor, T: BitStore, I: IntoIterator<Item=bool> { type Output = Self; /// `OR`s a vector and a bitstream, producing a new vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let lhs = bitvec![0, 1, 0, 1]; /// let rhs = bitvec![0, 0, 1, 1]; /// let or = lhs | rhs; /// assert_eq!("[0111]", &format!("{}", or)); /// ``` fn bitor(mut self, rhs: I) -> Self::Output { self |= rhs; self } } /// Performs the Boolean `OR` operation in place on a `BitVec`, using a stream /// of `bool` values as the other bit for each operation. If the other stream is /// shorter than `self`, `self` will be truncated when the other stream expires. impl<C, T, I> BitOrAssign<I> for BitVec<C, T> where C: Cursor, T: BitStore, I: IntoIterator<Item=bool> { /// `OR`s another bitstream into a vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut src = bitvec![0, 1, 0, 1]; /// src |= bitvec![0, 0, 1, 1]; /// assert_eq!("[0111]", &format!("{}", src)); /// ``` fn bitor_assign(&mut self, rhs: I) { // let mut len = 0; // for (idx, other) in (0 .. self.len()).zip(rhs.into_iter()) { // let val = self[idx] | other; // self.set(idx, val); // len += 1; // } let len = rhs.into_iter() .take(self.len()) .enumerate() .flat_map(|(i, r)| self.get(i).map(|l| self.set(i, l | r))) .count(); self.truncate(len); } } /// Performs the Boolean `XOR` operation between each element of a `BitVec` and /// anything that can provide a stream of `bool` values (such as another /// `BitVec`, or any `bool` generator of your choice). The `BitVec` emitted will /// have the length of the shorter sequence of bits -- if one is longer than the /// other, the extra bits will be ignored. impl<C, T, I> BitXor<I> for BitVec<C, T> where C: Cursor, T: BitStore, I: IntoIterator<Item=bool> { type Output = Self; /// `XOR`s a vector and a bitstream, producing a new vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let lhs = bitvec![0, 1, 0, 1]; /// let rhs = bitvec![0, 0, 1, 1]; /// let xor = lhs ^ rhs; /// assert_eq!("[0110]", &format!("{}", xor)); /// ``` fn bitxor(mut self, rhs: I) -> Self::Output { self ^= rhs; self } } /// Performs the Boolean `XOR` operation in place on a `BitVec`, using a stream /// of `bool` values as the other bit for each operation. If the other stream is /// shorter than `self`, `self` will be truncated when the other stream expires. impl<C, T, I> BitXorAssign<I> for BitVec<C, T> where C: Cursor, T: BitStore, I: IntoIterator<Item=bool> { /// `XOR`s another bitstream into a vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut src = bitvec![0, 1, 0, 1]; /// src ^= bitvec![0, 0, 1, 1]; /// assert_eq!("[0110]", &format!("{}", src)); /// ``` fn bitxor_assign(&mut self, rhs: I) { // let mut len = 0; // for (idx, other) in (0 .. self.len()).zip(rhs.into_iter()) { // let val = self[idx] ^ other; // self.set(idx, val); // len += 1; // } let len = rhs.into_iter() .take(self.len()) .enumerate() .flat_map(|(i, r)| self.get(i).map(|l| self.set(i, l ^ r))) .count(); self.truncate(len); } } /// Reborrows the `BitVec` as a `BitSlice`. /// /// This mimics the separation between `Vec<T>` and `[T]`. impl<C, T> Deref for BitVec<C, T> where C: Cursor, T: BitStore { type Target = BitSlice<C, T>; /// Dereferences `&BitVec` down to `&BitSlice`. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv: BitVec = bitvec![1; 4]; /// let bref: &BitSlice = &bv; /// assert!(bref[2]); /// ``` fn deref(&self) -> &Self::Target { self.as_bitslice() } } /// Mutably reborrows the `BitVec` as a `BitSlice`. /// /// This mimics the separation between `Vec<T>` and `[T]`. impl<C, T> DerefMut for BitVec<C, T> where C: Cursor, T: BitStore { /// Dereferences `&mut BitVec` down to `&mut BitSlice`. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv: BitVec = bitvec![0; 6]; /// let bref: &mut BitSlice = &mut bv; /// assert!(!bref[5]); /// bref.set(5, true); /// assert!(bref[5]); /// ``` fn deref_mut(&mut self) -> &mut Self::Target { self.as_mut_bitslice() } } /// Readies the underlying storage for Drop. impl<C, T> Drop for BitVec<C, T> where C: Cursor, T: BitStore { /// Rebuild the interior `Vec` and let it run the deallocator. fn drop(&mut self) { let bp = mem::replace(&mut self.pointer, BitPtr::empty()); // Build a Vec<T> out of the elements, and run its destructor. let (ptr, cap) = (bp.pointer(), self.capacity); drop(unsafe { Vec::from_raw_parts(ptr.w(), 0, cap) }); } } /// Gets the bit at a specific index. The index must be less than the length of /// the `BitVec`. impl<C, T> Index<usize> for BitVec<C, T> where C: Cursor, T: BitStore { type Output = bool; /// Looks up a single bit by semantic count. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![BigEndian, u8; 0, 0, 0, 0, 0, 0, 0, 0, 1, 0]; /// assert!(!bv[7]); // ---------------------------------^ | | /// assert!( bv[8]); // ------------------------------------^ | /// assert!(!bv[9]); // ---------------------------------------^ /// ``` /// /// If the index is greater than or equal to the length, indexing will /// panic. /// /// The below test will panic when accessing index 1, as only index 0 is /// valid. /// /// ```rust,should_panic /// use bitvec::prelude::*; /// /// let mut bv: BitVec = BitVec::new(); /// bv.push(true); /// bv[1]; /// ``` fn index(&self, cursor: usize) -> &Self::Output { &self.as_bitslice()[cursor] } } impl<C, T> Index<Range<usize>> for BitVec<C, T> where C: Cursor, T: BitStore { type Output = BitSlice<C, T>; fn index(&self, range: Range<usize>) -> &Self::Output { &self.as_bitslice()[range] } } impl<C, T> IndexMut<Range<usize>> for BitVec<C, T> where C: Cursor, T: BitStore { fn index_mut(&mut self, range: Range<usize>) -> &mut Self::Output { &mut self.as_mut_bitslice()[range] } } impl<C, T> Index<RangeFrom<usize>> for BitVec<C, T> where C: Cursor, T: BitStore { type Output = BitSlice<C, T>; fn index(&self, range: RangeFrom<usize>) -> &Self::Output { &self.as_bitslice()[range] } } impl<C, T> IndexMut<RangeFrom<usize>> for BitVec<C, T> where C: Cursor, T: BitStore { fn index_mut(&mut self, range: RangeFrom<usize>) -> &mut Self::Output { &mut self.as_mut_bitslice()[range] } } impl<C, T> Index<RangeFull> for BitVec<C, T> where C: Cursor, T: BitStore { type Output = BitSlice<C, T>; fn index(&self, _: RangeFull) -> &Self::Output { self.as_bitslice() } } impl<C, T> IndexMut<RangeFull> for BitVec<C, T> where C: Cursor, T: BitStore { fn index_mut(&mut self, _: RangeFull) -> &mut Self::Output { self.as_mut_bitslice() } } impl<C, T> Index<RangeInclusive<usize>> for BitVec<C, T> where C: Cursor, T: BitStore { type Output = BitSlice<C, T>; fn index(&self, range: RangeInclusive<usize>) -> &Self::Output { &self.as_bitslice()[range] } } impl<C, T> IndexMut<RangeInclusive<usize>> for BitVec<C, T> where C: Cursor, T: BitStore { fn index_mut(&mut self, range: RangeInclusive<usize>) -> &mut Self::Output { &mut self.as_mut_bitslice()[range] } } impl<C, T> Index<RangeTo<usize>> for BitVec<C, T> where C: Cursor, T: BitStore { type Output = BitSlice<C, T>; fn index(&self, range: RangeTo<usize>) -> &Self::Output { &self.as_bitslice()[range] } } impl<C, T> IndexMut<RangeTo<usize>> for BitVec<C, T> where C: Cursor, T: BitStore { fn index_mut(&mut self, range: RangeTo<usize>) -> &mut Self::Output { &mut self.as_mut_bitslice()[range] } } impl<C, T> Index<RangeToInclusive<usize>> for BitVec<C, T> where C: Cursor, T: BitStore { type Output = BitSlice<C, T>; fn index(&self, range: RangeToInclusive<usize>) -> &Self::Output { &self.as_bitslice()[range] } } impl<C, T> IndexMut<RangeToInclusive<usize>> for BitVec<C, T> where C: Cursor, T: BitStore { fn index_mut(&mut self, range: RangeToInclusive<usize>) -> &mut Self::Output { &mut self.as_mut_bitslice()[range] } } /// 2’s-complement negation of a `BitVec`. /// /// In 2’s-complement, negation is defined as bit-inversion followed by adding /// one. /// /// Numeric arithmetic is provided on `BitVec` as a convenience. Serious numeric /// computation on variable-length integers should use the `num_bigint` crate /// instead, which is written specifically for that use case. `BitVec`s are not /// intended for arithmetic, and `bitvec` makes no guarantees about sustained /// correctness in arithmetic at this time. impl<C, T> Neg for BitVec<C, T> where C: Cursor, T: BitStore { type Output = Self; /// Numerically negates a `BitVec` using 2’s-complement arithmetic. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![0, 1, 1]; /// let ne = -bv; /// assert_eq!(ne, bitvec![1, 0, 1]); /// ``` fn neg(mut self) -> Self::Output { // An empty vector does nothing. // Negative zero is zero. Without this check, -[0+] becomes[10+1]. if self.is_empty() || self.not_any() { return self; } self = !self; self += BitVec::<C, T>::from_iter(iter::once(true)); self } } /// Flips all bits in the vector. impl<C, T> Not for BitVec<C, T> where C: Cursor, T: BitStore { type Output = Self; /// Inverts all bits in the vector. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv: BitVec<BigEndian, u32> = BitVec::from(&[0u32] as &[u32]); /// let flip = !bv; /// assert_eq!(!0u32, flip.as_slice()[0]); /// ``` fn not(mut self) -> Self::Output { let _ = self.as_mut_bitslice().not(); self } } __bitvec_shift!(u8, u16, u32, u64, i8, i16, i32, i64); /// Shifts all bits in the vector to the left – **DOWN AND TOWARDS THE FRONT**. /// /// On primitives, the left-shift operator `<<` moves bits away from origin and /// towards the ceiling. This is because we label the bits in a primitive with /// the minimum on the right and the maximum on the left, which is big-endian /// bit order. This increases the value of the primitive being shifted. /// /// **THAT IS NOT HOW `BITVEC` WORKS!** /// /// `BitVec` defines its layout with the minimum on the left and the maximum on /// the right! Thus, left-shifting moves bits towards the **minimum**. /// /// In BigEndian order, the effect in memory will be what you expect the `<<` /// operator to do. /// /// **In LittleEndian order, the effect will be equivalent to using `>>` on** /// **the primitives in memory!** /// /// # Notes /// /// In order to preserve the effects in memory that this operator traditionally /// expects, the bits that are emptied by this operation are zeroed rather than /// left to their old value. /// /// The length of the vector is decreased by the shift amount. /// /// If the shift amount is greater than the length, the vector calls `clear()` /// and zeroes its memory. This is *not* an error. impl<C, T> Shl<usize> for BitVec<C, T> where C: Cursor, T: BitStore { type Output = Self; /// Shifts a `BitVec` to the left, shortening it. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![BigEndian, u8; 0, 0, 0, 1, 1, 1]; /// assert_eq!("[000111]", &format!("{}", bv)); /// assert_eq!(0b0001_1100, bv.as_slice()[0]); /// assert_eq!(bv.len(), 6); /// let ls = bv << 2usize; /// assert_eq!("[0111]", &format!("{}", ls)); /// assert_eq!(0b0111_0000, ls.as_slice()[0]); /// assert_eq!(ls.len(), 4); /// ``` fn shl(mut self, shamt: usize) -> Self::Output { self <<= shamt; self } } /// Shifts all bits in the vector to the left – **DOWN AND TOWARDS THE FRONT**. /// /// On primitives, the left-shift operator `<<` moves bits away from origin and /// towards the ceiling. This is because we label the bits in a primitive with /// the minimum on the right and the maximum on the left, which is big-endian /// bit order. This increases the value of the primitive being shifted. /// /// **THAT IS NOT HOW `BITVEC` WORKS!** /// /// `BitVec` defines its layout with the minimum on the left and the maximum on /// the right! Thus, left-shifting moves bits towards the **minimum**. /// /// In BigEndian order, the effect in memory will be what you expect the `<<` /// operator to do. /// /// **In LittleEndian order, the effect will be equivalent to using `>>` on** /// **the primitives in memory!** /// /// # Notes /// /// In order to preserve the effects in memory that this operator traditionally /// expects, the bits that are emptied by this operation are zeroed rather than /// left to their old value. /// /// The length of the vector is decreased by the shift amount. /// /// If the shift amount is greater than the length, the vector calls `clear()` /// and zeroes its memory. This is *not* an error. impl<C, T> ShlAssign<usize> for BitVec<C, T> where C: Cursor, T: BitStore { /// Shifts a `BitVec` to the left in place, shortening it. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![LittleEndian, u8; 0, 0, 0, 1, 1, 1]; /// assert_eq!("[000111]", &format!("{}", bv)); /// assert_eq!(0b0011_1000, bv.as_slice()[0]); /// assert_eq!(bv.len(), 6); /// bv <<= 2; /// assert_eq!("[0111]", &format!("{}", bv)); /// assert_eq!(0b0000_1110, bv.as_slice()[0]); /// assert_eq!(bv.len(), 4); /// ``` fn shl_assign(&mut self, shamt: usize) { let len = self.len(); if shamt >= len { self.set_all(false); self.clear(); return; } for idx in shamt .. len { let val = self[idx]; self.set(idx.saturating_sub(shamt), val); } let trunc = len.saturating_sub(shamt); for idx in trunc .. len { self.set(idx, false); } self.truncate(trunc); } } /// Shifts all bits in the vector to the right – **UP AND TOWARDS THE BACK**. /// /// On primitives, the right-shift operator `>>` moves bits towards the origin /// and away from the ceiling. This is because we label the bits in a primitive /// with the minimum on the right and the maximum on the left, which is /// big-endian bit order. This decreases the value of the primitive being /// shifted. /// /// **THAT IS NOT HOW `BITVEC` WORKS!** /// /// `BitVec` defines its layout with the minimum on the left and the maximum on /// the right! Thus, right-shifting moves bits towards the **maximum**. /// /// In BigEndian order, the effect in memory will be what you expect the `>>` /// operator to do. /// /// **In LittleEndian order, the effect will be equivalent to using `<<` on** /// **the primitives in memory!** /// /// # Notes /// /// In order to preserve the effects in memory that this operator traditionally /// expects, the bits that are emptied by this operation are zeroed rather than /// left to their old value. /// /// The length of the vector is increased by the shift amount. /// /// If the new length of the vector would overflow, a panic occurs. This *is* an /// error. impl<C, T> Shr<usize> for BitVec<C, T> where C: Cursor, T: BitStore { type Output = Self; /// Shifts a `BitVec` to the right, lengthening it and filling the front /// with 0. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![BigEndian, u8; 0, 0, 0, 1, 1, 1]; /// assert_eq!("[000111]", &format!("{}", bv)); /// assert_eq!(0b0001_1100, bv.as_slice()[0]); /// assert_eq!(bv.len(), 6); /// let rs = bv >> 2usize; /// assert_eq!("[00000111]", &format!("{}", rs)); /// assert_eq!(0b0000_0111, rs.as_slice()[0]); /// assert_eq!(rs.len(), 8); /// ``` fn shr(mut self, shamt: usize) -> Self::Output { self >>= shamt; self } } /// Shifts all bits in the vector to the right – **UP AND TOWARDS THE BACK**. /// /// On primitives, the right-shift operator `>>` moves bits towards the origin /// and away from the ceiling. This is because we label the bits in a primitive /// with the minimum on the right and the maximum on the left, which is /// big-endian bit order. This decreases the value of the primitive being /// shifted. /// /// **THAT IS NOT HOW `BITVEC` WORKS!** /// /// `BitVec` defines its layout with the minimum on the left and the maximum on /// the right! Thus, right-shifting moves bits towards the **maximum**. /// /// In BigEndian order, the effect in memory will be what you expect the `>>` /// operator to do. /// /// **In LittleEndian order, the effect will be equivalent to using `<<` on** /// **the primitives in memory!** /// /// # Notes /// /// In order to preserve the effects in memory that this operator traditionally /// expects, the bits that are emptied by this operation are zeroed rather than /// left to their old value. /// /// The length of the vector is increased by the shift amount. /// /// If the new length of the vector would overflow, a panic occurs. This *is* an /// error. impl<C, T> ShrAssign<usize> for BitVec<C, T> where C: Cursor, T: BitStore { /// Shifts a `BitVec` to the right in place, lengthening it and filling the /// front with 0. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let mut bv = bitvec![LittleEndian, u8; 0, 0, 0, 1, 1, 1]; /// assert_eq!("[000111]", &format!("{}", bv)); /// assert_eq!(0b0011_1000, bv.as_slice()[0]); /// assert_eq!(bv.len(), 6); /// bv >>= 2; /// assert_eq!("[00000111]", &format!("{}", bv)); /// assert_eq!(0b1110_0000, bv.as_slice()[0]); /// assert_eq!(bv.len(), 8); /// ``` fn shr_assign(&mut self, shamt: usize) { let old_len = self.len(); for _ in 0 .. shamt { self.push(false); } for idx in (0 .. old_len).rev() { let val = self[idx]; self.set(idx.saturating_add(shamt), val); } for idx in 0 .. shamt { self.set(idx, false); } } } /// Subtracts one `BitVec` from another assuming 2’s-complement encoding. /// /// Subtraction is a more complex operation than addition. The bit-level work is /// largely the same, but semantic distinctions must be made. Unlike addition, /// which is commutative and tolerant of switching the order of the addends, /// subtraction cannot swap the minuend (LHS) and subtrahend (RHS). /// /// Because of the properties of 2’s-complement arithmetic, M - S is equivalent /// to M + (!S + 1). Subtraction therefore bitflips the subtrahend and adds one. /// This may, in a degenerate case, cause the subtrahend to increase in length. /// /// Once the subtrahend is stable, the minuend zero-extends its left side in /// order to match the length of the subtrahend if needed (this is provided by /// the `>>` operator). /// /// When the minuend is stable, the minuend and subtrahend are added together /// by the `<BitVec as Add>` implementation. The output will be encoded in /// 2’s-complement, so a leading one means that the output is considered /// negative. /// /// Interpreting the contents of a `BitVec` as an integer is beyond the scope of /// this crate. /// /// Numeric arithmetic is provided on `BitVec` as a convenience. Serious numeric /// computation on variable-length integers should use the `num_bigint` crate /// instead, which is written specifically for that use case. `BitVec`s are not /// intended for arithmetic, and `bitvec` makes no guarantees about sustained /// correctness in arithmetic at this time. impl<C, T> Sub for BitVec<C, T> where C: Cursor, T: BitStore { type Output = Self; /// Subtracts one `BitVec` from another. /// /// # Examples /// /// Minuend larger than subtrahend, positive difference. /// /// ```rust /// use bitvec::prelude::*; /// /// let a = bitvec![1, 0]; /// let b = bitvec![ 1]; /// let c = a - b; /// assert_eq!(bitvec![0, 1], c); /// ``` /// /// Minuend smaller than subtrahend, negative difference. /// /// ```rust /// use bitvec::prelude::*; /// /// let a = bitvec![ 1]; /// let b = bitvec![1, 0]; /// let c = a - b; /// assert_eq!(bitvec![1, 1], c); /// ``` /// /// Subtraction from self is correctly handled. /// /// ```rust /// use bitvec::prelude::*; /// /// let a = bitvec![0, 1, 1, 0]; /// let b = a.clone(); /// let c = a - b; /// assert!(c.not_any(), "{:?}", c); /// ``` fn sub(mut self, subtrahend: Self) -> Self::Output { self -= subtrahend; self } } /// Subtracts another `BitVec` from `self`, assuming 2’s-complement encoding. /// /// The minuend is zero-extended, or the subtrahend sign-extended, as needed to /// ensure that the vectors are the same width before subtraction occurs. /// /// The `Sub` trait has more documentation on the subtraction process. /// /// Numeric arithmetic is provided on `BitVec` as a convenience. Serious numeric /// computation on variable-length integers should use the `num_bigint` crate /// instead, which is written specifically for that use case. `BitVec`s are not /// intended for arithmetic, and `bitvec` makes no guarantees about sustained /// correctness in arithmetic at this time. impl<C, T> SubAssign for BitVec<C, T> where C: Cursor, T: BitStore { /// Subtracts another `BitVec` from `self`. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let a = bitvec![0, 0, 0, 1]; /// let b = bitvec![0, 0, 0, 0]; /// let c = a - b; /// assert_eq!(c, bitvec![0, 0, 0, 1]); /// ``` // Note: in `a - b`, `a` is `self` and the minuend, `b` is the subtrahend fn sub_assign(&mut self, mut subtrahend: Self) { // Test for a zero subtrahend. Subtraction of zero is the identity // function, and can exit immediately. if subtrahend.not_any() { return; } // Invert the subtrahend in preparation for addition subtrahend = -subtrahend; let (llen, rlen) = (self.len(), subtrahend.len()); // If the subtrahend is longer than the minuend, 0-extend the minuend. if rlen > llen { let diff = rlen - llen; *self >>= diff; } else { // If the minuend is longer than the subtrahend, sign-extend the // subtrahend. if llen > rlen { let diff = llen - rlen; let sign = subtrahend[0]; subtrahend >>= diff; subtrahend[.. diff].set_all(sign); } } let old = self.len(); *self += subtrahend; // If the subtraction emitted a carry, remove it. if self.len() > old { *self <<= 1; } } } /// State keeper for draining iteration. /// /// # Type Parameters /// /// - `C: Cursor`: The cursor type of the underlying vector. /// - `T: 'a + BitStore`: The storage type of the underlying vector. /// /// # Lifetimes /// /// - `'a`: The lifetime of the underlying vector. pub struct Drain<'a, C, T> where C: Cursor, T: 'a + BitStore { /// Pointer to the `BitVec` being drained. bitvec: NonNull<BitVec<C, T>>, /// Current remaining range to remove. iter: crate::slice::Iter<'a, C, T>, /// Index of the original vector tail to preserve. tail_start: usize, /// Length of the tail. tail_len: usize, } impl<'a, C, T> Drain<'a, C, T> where C: Cursor, T: 'a + BitStore { /// Fills the drain span with another iterator. /// /// If the stream exhausts before the drain is filled, then the tail /// elements move downwards; otherwise, the tail stays put and the drain is /// filled. /// /// # Parameters /// /// - `&mut self` /// - `stream`: The source of bits to fill into the drain. /// /// # Returns /// /// - `true` if the drain was filled before the `stream` exhausted. /// - `false` if the `stream` exhausted early, and the tail was moved down. /// /// # Type Parameters /// /// - `I: Iterator<Item=bool>`: A provider of bits. unsafe fn fill<I: Iterator<Item=bool>>(&mut self, stream: &mut I) -> bool { let bv = self.bitvec.as_mut(); let drain_from = bv.len(); let drain_upto = self.tail_start; for n in drain_from .. drain_upto { if let Some(bit) = stream.next() { bv.push(bit); } else { for (to, from) in (n .. n + self.tail_len).zip(drain_upto ..) { bv.swap(from, to); } self.tail_start = n; return false; } } true } /// Moves the tail span farther back in the vector. /// /// # Parameters /// /// - `&mut self` /// - `by`: The amount by which to move the tail span. unsafe fn move_tail(&mut self, by: usize) { let bv = self.bitvec.as_mut(); bv.reserve(by); let new_tail = self.tail_start + by; let old_len = bv.len(); let new_len = self.tail_start + self.tail_len + by; bv.set_len(new_len); for n in (0 .. self.tail_len).rev() { bv.swap(self.tail_start + n, new_tail + n); } bv.set_len(old_len); self.tail_start = new_tail; } } impl<'a, C, T> DoubleEndedIterator for Drain<'a, C, T> where C: Cursor, T: 'a + BitStore { fn next_back(&mut self) -> Option<Self::Item> { self.iter.next_back() } } impl<'a, C, T> ExactSizeIterator for Drain<'a, C, T> where C: Cursor, T: 'a + BitStore {} impl<'a, C, T> FusedIterator for Drain<'a, C, T> where C: Cursor, T: 'a + BitStore {} impl<'a, C, T> Iterator for Drain<'a, C, T> where C: Cursor, T: 'a + BitStore { type Item = bool; fn next(&mut self) -> Option<Self::Item> { self.iter.next() } fn size_hint(&self) -> (usize, Option<usize>) { self.iter.size_hint() } fn count(self) -> usize { self.len() } fn nth(&mut self, n: usize) -> Option<Self::Item> { self.iter.nth(n) } fn last(mut self) -> Option<Self::Item> { self.iter.next_back() } } impl<'a, C, T> Drop for Drain<'a, C, T> where C: Cursor, T: 'a + BitStore { fn drop(&mut self) { unsafe { let bv: &mut BitVec<C, T> = self.bitvec.as_mut(); // Get the start of the drained span. let start = bv.len(); // Get the start of the remnant span. let tail = self.tail_start; let tail_len = self.tail_len; // Get the full length of the vector, let full_len = tail + tail_len; // And the length of the vector after the drain. let end_len = start + tail_len; // Inflate the vector to include the remnant span, bv.set_len(full_len); // Swap the remnant span down into the drained span, for (from, to) in (tail .. full_len).zip(start .. end_len) { bv.swap(from, to); } // And deflate the vector to fit. bv.set_len(end_len); } } } /// A consuming iterator for `BitVec`. #[repr(C)] pub struct IntoIter<C, T> where C: Cursor, T: BitStore { /// Owning descriptor for the allocation. This is not modified by iteration. bitvec: BitVec<C, T>, /// Descriptor for the live portion of the vector as iteration proceeds. region: BitPtr<T>, } impl<C, T> IntoIter<C, T> where C: Cursor, T: BitStore { fn iterator(&self) -> <&BitSlice<C, T> as IntoIterator>::IntoIter { self.region.into_bitslice().into_iter() } } impl<C, T> DoubleEndedIterator for IntoIter<C, T> where C: Cursor, T: BitStore { fn next_back(&mut self) -> Option<Self::Item> { let mut slice_iter = self.iterator(); let out = slice_iter.next_back(); self.region = slice_iter.bitptr(); out } } impl<C, T> ExactSizeIterator for IntoIter<C, T> where C: Cursor, T: BitStore {} impl<C, T> FusedIterator for IntoIter<C, T> where C: Cursor, T: BitStore {} impl<C, T> Iterator for IntoIter<C, T> where C: Cursor, T: BitStore { type Item = bool; /// Advances the iterator by one, returning the first bit in it (if any). /// /// # Parameters /// /// - `&mut self` /// /// # Returns /// /// The leading bit in the iterator, if any. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![1, 0]; /// let mut iter = bv.iter(); /// assert!(iter.next().unwrap()); /// assert!(!iter.next().unwrap()); /// assert!(iter.next().is_none()); /// ``` fn next(&mut self) -> Option<Self::Item> { let mut slice_iter = self.iterator(); let out = slice_iter.next(); self.region = slice_iter.bitptr(); out } /// Hints at the number of bits remaining in the iterator. /// /// Because the exact size is always known, this always produces /// `(len, Some(len))`. /// /// # Parameters /// /// - `&self` /// /// # Returns /// /// - `usize`: The minimum bits remaining. /// - `Option<usize>`: The maximum bits remaining. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// /// let bv = bitvec![0, 1]; /// let mut iter = bv.iter(); /// assert_eq!(iter.size_hint(), (2, Some(2))); /// iter.next(); /// assert_eq!(iter.size_hint(), (1, Some(1))); /// iter.next(); /// assert_eq!(iter.size_hint(), (0, Some(0))); /// ``` fn size_hint(&self) -> (usize, Option<usize>) { self.iterator().size_hint() } /// Counts how many bits are live in the iterator, consuming it. /// /// You are probably looking to use this on a borrowed iterator rather than /// an owning iterator. See [`BitSlice`]. /// /// # Parameters /// /// - `self` /// /// # Returns /// /// The number of bits in the iterator. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// let bv = bitvec![BigEndian, u8; 0, 1, 0, 1, 0]; /// assert_eq!(bv.into_iter().count(), 5); /// ``` /// /// [`BitSlice`]: ../struct.BitSlice.html#method.iter fn count(self) -> usize { self.bitvec.len() } /// Advances the iterator by `n` bits, starting from zero. /// /// # Parameters /// /// - `&mut self` /// - `n`: The number of bits to skip, before producing the next bit after /// skips. If this overshoots the iterator’s remaining length, then the /// iterator is marked empty before returning `None`. /// /// # Returns /// /// If `n` does not overshoot the iterator’s bounds, this produces the `n`th /// bit after advancing the iterator to it, discarding the intermediate /// bits. /// /// If `n` does overshoot the iterator’s bounds, this empties the iterator /// and returns `None`. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// let bv = bitvec![BigEndian, u8; 0, 0, 0, 1]; /// let mut iter = bv.into_iter(); /// assert_eq!(iter.len(), 4); /// assert!(iter.nth(3).unwrap()); /// assert!(iter.nth(0).is_none()); /// ``` fn nth(&mut self, n: usize) -> Option<Self::Item> { let mut slice_iter = self.iterator(); let out = slice_iter.nth(n); self.region = slice_iter.bitptr(); out } /// Consumes the iterator, returning only the last bit. /// /// # Examples /// /// ```rust /// use bitvec::prelude::*; /// let bv = bitvec![BigEndian, u8; 0, 0, 0, 1]; /// assert!(bv.into_iter().last().unwrap()); /// ``` /// /// Empty iterators return `None` /// /// ```rust /// use bitvec::prelude::*; /// assert!(bitvec![].into_iter().last().is_none()); /// ``` fn last(mut self) -> Option<Self::Item> { self.next_back() } } /// A splicing iterator for `BitVec`. /// /// This removes a segment from the vector and inserts another bitstream into /// its spot. Any bits from the original `BitVec` after the removed segment are /// kept, after the inserted bitstream. /// /// Only the removed segment is available for iteration. /// /// # Type Parameters /// /// - `I: Iterator<Item=bool>`: Any bitstream. This will be used to fill the /// removed span. pub struct Splice<'a, C, T, I> where C: Cursor, T: 'a + BitStore, I: Iterator<Item=bool> { drain: Drain<'a, C, T>, splice: I, } impl<'a, C, T, I> DoubleEndedIterator for Splice<'a, C, T, I> where C: Cursor, T: 'a + BitStore, I: Iterator<Item=bool> { fn next_back(&mut self) -> Option<Self::Item> { self.drain.next_back() } } impl<'a, C, T, I> ExactSizeIterator for Splice<'a, C, T, I> where C: Cursor, T: 'a + BitStore, I: Iterator<Item=bool> {} impl<'a, C, T, I> FusedIterator for Splice<'a, C, T, I> where C: Cursor, T: 'a + BitStore, I: Iterator<Item=bool> {} // Forward iteration to the interior drain impl<'a, C, T, I> Iterator for Splice<'a, C, T, I> where C: Cursor, T: 'a + BitStore, I: Iterator<Item=bool> { type Item = bool; fn next(&mut self) -> Option<Self::Item> { // If the drain produced a bit, then try to pull a bit from the // replacement. If the replacement produced a bit, push it into the // `BitVec` that the drain is managing. This works because the `Drain` // type truncates the `BitVec` to the front of the region being // drained, then tracks the remainder of the memory. self.drain.next().map(|bit| { if let Some(new_bit) = self.splice.next() { unsafe { self.drain.bitvec.as_mut() }.push(new_bit); } bit }) } fn size_hint(&self) -> (usize, Option<usize>) { self.drain.size_hint() } fn count(self) -> usize { self.drain.len() } fn nth(&mut self, n: usize) -> Option<Self::Item> { self.drain.nth(n) } fn last(mut self) -> Option<Self::Item> { self.drain.next_back() } } impl<'a, C, T, I> Drop for Splice<'a, C, T, I> where C: Cursor, T: 'a + BitStore, I: Iterator<Item=bool> { fn drop(&mut self) { unsafe { if self.drain.tail_len == 0 { self.drain.bitvec.as_mut().extend(self.splice.by_ref()); return; } // Fill the drained span from the splice. If this exhausts the splice, // exit. Note that `Drain::fill` runs from the current `BitVec.len` // value, so the fact that `Splice::next` attempts to push onto the // vector is not a problem here. if !self.drain.fill(&mut self.splice) { return; } let (lower, _) = self.splice.size_hint(); // If the splice still has data, move the tail to make room for it and // fill. if lower > 0 { self.drain.move_tail(lower); if !self.drain.fill(&mut self.splice) { return; } } let mut remnant = self.splice.by_ref().collect::<Vec<_>>().into_iter(); if remnant.len() > 0 { self.drain.move_tail(remnant.len()); self.drain.fill(&mut remnant); } // Drain::drop does the rest } } }