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
//! Voluntary Servitude Foreign Function Interface (FFI)
//!
//! Allows using this rust library as a C library
//!
//! While `vs_t` ([`VoluntaryServitude`] in C) is thread-safe it's your responsibility to make sure it exists while pointers to it exist
//!
//! [`VoluntaryServitude`]: ../struct.VoluntaryServitude.html
//!
//! # Single-thread C implementation
//!
//! ```c
//! #include<assert.h>
//! #include<stdio.h>
//! #include "../include/voluntary_servitude.h"
//!
//! int main(int argc, char **argv) {
//! // You are responsible for making sure 'vs' exists while accessed
//! vs_t * vs = vs_new();
//!
//! // Current vs_t length
//! // Be careful with data-races since the value, when used, may not be true anymore
//! assert(vs_len(vs) == 0);
//!
//! const unsigned int data[2] = {12, 25};
//! // Inserts void pointer to data to end of vs_t
//! vs_append(vs, (void *) &data[0]);
//! vs_append(vs, (void *) &data[1]);
//!
//! // Creates a one-time lock-free iterator based on vs_t
//! vs_iter_t * iter = vs_iter(vs);
//!
//! // Clearing vs_t, doesn't change existing iterators
//! vs_clear(vs);
//! assert(vs_len(vs) == 0);
//! assert(vs_iter_len(iter) == 2);
//!
//! assert(*(unsigned int *) vs_iter_next(iter) == 12);
//! // Index changes as you iter through vs_iter_t
//! assert(vs_iter_index(iter) == 1);
//! assert(*(unsigned int *) vs_iter_next(iter) == 25);
//! assert(vs_iter_index(iter) == 2);
//!
//! assert(vs_iter_next(iter) == NULL);
//! assert(vs_iter_index(iter) == 2);
//! // Index doesn't increase after it gets equal to 'len'
//! // Length also is unable to increase after iterator is consumed
//! assert(vs_iter_index(iter) == vs_iter_len(iter));
//!
//! // Never forget to free vs_iter_t
//! assert(vs_iter_destroy(iter) == 0);
//!
//! // Create updated vs_iter_t
//! vs_iter_t * iter2 = vs_iter(vs);
//!
//! // Never forget to free vs_t
//! assert(vs_destroy(vs) == 0);
//!
//! // vs_iter_t keeps existing after the original vs_t is freed (or cleared)
//! assert(vs_iter_len(iter2) == 0);
//! assert(vs_iter_next(iter2) == NULL);
//! assert(vs_iter_index(iter2) == 0);
//!
//! assert(vs_iter_destroy(iter2) == 0);
//!
//! printf("Single thread example ended without errors\n");
//! (void) argc;
//! (void) argv;
//! return 0;
//! }
//! ```
//!
//! # Multi-thread C implementation
//!
//! ```c
//! #include<pthread.h>
//! #include<assert.h>
//! #include<stdio.h>
//! #include "../include/voluntary_servitude.h"
//!
//! const unsigned int num_producers = 4;
//! const unsigned int num_consumers = 8;
//!
//! const unsigned int num_producer_values = 1000;
//! const unsigned int data[3] = {12, 25, 89};
//! const size_t last_index = sizeof(data) / sizeof(data[0]) - 1;
//!
//! void * producer();
//! void * consumer();
//!
//! int main(int argc, char** argv) {
//! // You are responsible for making sure 'vs' exists
//! // while the producers and consumers do
//! vs_t * const vs = vs_new();
//! unsigned int current_thread = 0;
//! pthread_attr_t attr;
//! pthread_t consumers[num_consumers],
//! producers[num_producers];
//!
//! if (pthread_attr_init(&attr) != 0) {
//! fprintf(stderr, "Failed to initialize pthread arguments.\n");
//! exit(-1);
//! }
//!
//! // Creates producer threads
//! for (current_thread = 0; current_thread < num_producers; ++current_thread) {
//! if (pthread_create(&producers[current_thread], &attr, &producer, (void *) vs) != 0) {
//! fprintf(stderr, "Failed to create producer thread %d.\n", current_thread);
//! exit(-2);
//! }
//!
//! }
//!
//! // Creates consumers threads
//! for (current_thread = 0; current_thread < num_consumers; ++current_thread) {
//! if (pthread_create(&consumers[current_thread], &attr, &consumer, (void *) vs) != 0) {
//! fprintf(stderr, "Failed to create consumer thread %d.\n", current_thread);
//! exit(-3);
//! }
//! }
//!
//! // Join all threads, ensuring vs_t* is not used anymore
//! for (current_thread = 0; current_thread < num_producers; ++current_thread) {
//! pthread_join(producers[current_thread], NULL);
//! }
//! for (current_thread = 0; current_thread < num_consumers; ++current_thread) {
//! pthread_join(consumers[current_thread], NULL);
//! }
//!
//! // Never forget to free the memory allocated through rust
//! assert(vs_destroy(vs) == 0);
//!
//! printf("Multi thread example ended without errors\n");
//! (void) argc;
//! (void) argv;
//! return 0;
//! }
//!
//!
//! void * producer(void * const vs){
//! unsigned int index;
//! for (index = 0; index < num_producer_values; ++index) {
//! assert(vs_append(vs, (void *) &data[index % last_index]) == 0);
//! }
//! return NULL;
//! }
//!
//! void * consumer(void * const vs) {
//! const unsigned int total_values = num_producers * num_producer_values;
//! unsigned int values;
//!
//! while (values < total_values) {
//! unsigned int sum = (values = 0);
//! vs_iter_t * const iter = vs_iter(vs);
//! const void * value;
//!
//! while ((value = vs_iter_next(iter)) != NULL) {
//! ++values;
//! sum += *(unsigned int *) value;
//! }
//! printf("Consumer counts %d elements summing %d.\n", values, sum);
//!
//! assert(vs_iter_destroy(iter) == 0);
//! }
//! return NULL;
//! }
//! ```
use iterator::VSIter;
use std::{mem::drop, ptr::null_mut};
pub use std::os::raw::c_void;
use voluntary_servitude::VoluntaryServitude;
/// Initialize logger according to RUST_LOG env var (exists behind 'logs' feature)
///
/// ```bash
/// export RUST_LOG=vs=trace
/// export RUST_LOG=vs=debug
/// export RUST_LOG=vs=info
/// export RUST_LOG=vs=warn
/// export RUST_LOG=vs=error
/// ```
///
/// Feature to enable it:
///
/// ```bash
/// cargo build --features "logs"
/// ```
///
/// ```rust
/// use voluntary_servitude::ffi::*;
/// unsafe { initialize_logger() }
/// ```
#[no_mangle]
#[cfg(feature = "logs")]
pub unsafe extern "C" fn initialize_logger() {
::setup_logger();
}
/// Creates new empty [`VoluntaryServitude`]
///
/// `vs_drop` should be called eventually for [`VoluntaryServitude`] returned, otherwise memory will leak
///
/// [`VoluntaryServitude`]: ../struct.VoluntaryServitude.html
///
/// # Rust
///
/// ```rust
/// use voluntary_servitude::ffi::*;
/// unsafe {
/// # #[cfg(feature = "logs")] initialize_logger();
/// let vs = vs_new();
/// assert_eq!(vs_len(vs), 0);
/// assert_eq!(vs_destroy(vs), 0);
/// }
/// ```
///
/// # C
///
/// ```c
/// #include<assert.h>
/// #include "../include/voluntary_servitude.h"
///
/// int main(int argc, char **argv) {
/// vs_t * vs = vs_new();
/// assert(vs_len(vs) == 0);
/// assert(vs_destroy(vs) == 0);
/// return 0;
/// }
/// ```
#[no_mangle]
pub unsafe extern "C" fn vs_new() -> *mut VoluntaryServitude<*const c_void> {
Box::into_raw(Box::new(vs![]))
}
/// Makes lock-free iterator based on [`VoluntaryServitude`]
///
/// `vs_iter_drop` should be called eventually for [`VSIter`] returned, otherwise memory will leak
///
/// Returns NULL if pointer to [`VoluntaryServitude`] is NULL
///
/// Warning: UB if pointer to [`VoluntaryServitude`] is invalid
///
/// [`VoluntaryServitude`]: ../struct.VoluntaryServitude.html
/// [`VSIter`]: ../type.VSIter.html
///
/// # Rust
///
/// ```rust
/// use std::ptr::null_mut;
/// use voluntary_servitude::ffi::*;
///
/// unsafe {
/// # #[cfg(feature = "logs")] initialize_logger();
/// let vs = vs_new();
/// let data: i32 = 3;
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// let iter = vs_iter(vs);
/// assert_eq!(vs_destroy(vs), 0);
/// assert_eq!(*(vs_iter_next(iter) as *const i32), 3);
/// assert!(vs_iter_next(iter).is_null());
/// assert_eq!(vs_iter_destroy(iter), 0);
///
/// // Propagates NULL pointers
/// assert_eq!(vs_iter(null_mut()), null_mut());
/// }
/// ```
///
/// # C
///
/// ```c
/// #include<assert.h>
/// #include "../include/voluntary_servitude.h"
///
/// int main(int argc, char **argv) {
/// vs_t * vs = vs_new();
/// vs_iter_t * iter = vs_iter(vs);
/// const unsigned int data = 3;
/// assert(vs_append(vs, (void *) &data) == 0);
/// vs_iter_t * iter2 = vs_iter(vs);
/// assert(vs_destroy(iter) == 0);
/// assert(*(unsigned int *) vs_iter_next(iter2) == 3);
/// assert(vs_iter_next(iter2) == NULL);
///
/// assert(vs_iter_destroy(iter2) == 0);
///
/// // Propagates NULL pointers
/// assert(vs_iter(NULL) == NULL);
/// return 0;
/// }
/// ```
#[no_mangle]
pub unsafe extern "C" fn vs_iter<'a>(
vs: *mut VoluntaryServitude<*const c_void>,
) -> *mut VSIter<'a, *const c_void> {
null_check!(vs, null_mut());
Box::into_raw(Box::new((*vs).iter()))
}
/// Atomically extracts current size of [`VoluntaryServitude`], be careful with data-races when using it
///
/// Returns 0 if pointer to [`VoluntaryServitude`] is NULL
///
/// Warning: UB if pointer to [`VoluntaryServitude`] invalid
///
/// [`VoluntaryServitude`]: ../struct.VoluntaryServitude.html
///
/// # Rust
///
/// ```rust
/// use std::ptr::null_mut;
/// use voluntary_servitude::ffi::*;
///
/// unsafe {
/// # #[cfg(feature = "logs")] initialize_logger();
/// let vs = vs_new();
/// assert_eq!(vs_len(vs), 0);
/// let data: i32 = 5;
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// assert_eq!(vs_len(vs), 1);
/// assert_eq!(vs_destroy(vs), 0);
///
/// // 0 length on NULL pointer
/// assert_eq!(vs_len(null_mut()), 0);
/// }
/// ```
///
/// # C
///
/// ```c
/// #include<assert.h>
/// #include "../include/voluntary_servitude.h"
///
/// int main(int argc, char **argv) {
/// vs_t * vs = vs_new();
/// assert(vs_len(vs) == 0);
///
/// const unsigned int data = 5;
/// assert(vs_append(vs, (void *) &data) == 0);
/// assert(vs_len(vs) == 1);
/// assert(vs_destroy(vs) == 0);
///
/// // 0 length on NULL pointer
/// assert(vs_len(NULL) == 0);
/// return 0;
/// }
/// ```
#[no_mangle]
pub unsafe extern "C" fn vs_len(list: *const VoluntaryServitude<*const c_void>) -> usize {
null_check!(list, 0);
(*list).len()
}
/// Append element to [`VoluntaryServitude`]
///
/// Returns 1 if pointer to [`VoluntaryServitude`] is NULL
///
/// Returns 0 otherwise
///
/// Warning: UB if pointer to [`VoluntaryServitude`] is invalid
///
/// [`VoluntaryServitude`]: ../struct.VoluntaryServitude.html
///
/// # Rust
///
/// ```rust
/// use std::ptr::null_mut;
/// use voluntary_servitude::ffi::*;
///
/// unsafe {
/// # #[cfg(feature = "logs")] initialize_logger();
/// let vs = vs_new();
/// let data: i32 = 5;
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// let iter = vs_iter(vs);
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// assert_eq!(*(vs_iter_next(iter) as *const i32), 5);
/// assert_eq!(*(vs_iter_next(iter) as *const i32), 5);
/// assert_eq!(vs_iter_destroy(iter), 0);
/// assert_eq!(vs_destroy(vs), 0);
///
/// // Returns 1 on NULL pointer
/// assert_eq!(vs_append(null_mut(), &data as *const i32 as *const c_void), 1);
/// }
/// ```
///
/// # C
///
/// ```c
/// #include<assert.h>
/// #include "../include/voluntary_servitude.h"
///
/// int main(int argc, char **argv) {
/// vs_t * vs = vs_new();
/// const unsigned int data = 5;
/// assert(vs_append(vs, (void *) &data) == 0);
/// vs_iter_t * iter = vs_iter(vs);
/// assert(vs_append(vs, (void *) &data) == 0);
/// assert(*(unsigned int *) vs_iter_next(iter) == 5);
/// assert(*(unsigned int *) vs_iter_next(iter) == 5);
///
/// assert(vs_iter_destroy(iter) == 0);
/// assert(vs_destroy(vs) == 0);
///
/// // Returns 1 on NULL pointer
/// assert(vs_append(NULL, (void *) &data) == 1);
/// return 0;
/// }
/// ```
#[no_mangle]
pub unsafe extern "C" fn vs_append(
list: *mut VoluntaryServitude<*const c_void>,
element: *const c_void,
) -> u8 {
null_check!(list, 1);
(*list).append(element);
0
}
/// Removes all elements from list (preserves existing iterators)
///
/// Returns 1 if pointer to [`VoluntaryServitude`] is NULL
///
/// Returns 0 otherwise
///
/// Warning: UB if pointer to [`VoluntaryServitude`] is invalid
///
/// [`VoluntaryServitude`]: ../struct.VoluntaryServitude.html
///
/// # Rust
///
/// ```rust
/// use std::ptr::null_mut;
/// use voluntary_servitude::ffi::*;
///
/// unsafe {
/// # #[cfg(feature = "logs")] initialize_logger();
/// let vs = vs_new();
/// let data: i32 = 5;
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// assert_eq!(vs_len(vs), 1);
/// assert_eq!(vs_clear(vs), 0);
/// assert_eq!(vs_len(vs), 0);
///
/// // Returns 1 on NULL pointer
/// assert_eq!(vs_clear(null_mut()), 1);
/// }
/// ```
///
/// # C
///
/// ```c
/// #include<assert.h>
/// #include "../include/voluntary_servitude.h"
///
/// int main(int argc, char **argv) {
/// vs_t * vs = vs_new();
/// const unsigned int data = 5;
/// assert(vs_append(vs, (void *) &data) == 0);
/// assert(vs_len(vs) == 1);
/// assert(vs_clear(vs) == 0);
/// assert(vs_len(vs) == 0);
///
/// // Returns 1 on NULL pointer
/// assert(vs_clear(NULL) == 1);
/// return 0;
/// }
/// ```
#[no_mangle]
pub unsafe extern "C" fn vs_clear(list: *mut VoluntaryServitude<*const c_void>) -> u8 {
null_check!(list, 1);
(*list).clear();
0
}
/// Free [`VoluntaryServitude`] (preserves existing iterators)
///
/// Returns 1 if pointer to [`VoluntaryServitude`] is NULL
///
/// Returns 0 otherwise
///
/// Warning: UB if pointer to [`VoluntaryServitude`] is invalid
///
/// [`VoluntaryServitude`]: ../struct.VoluntaryServitude.html
///
/// # Rust
///
/// ```rust
/// use std::ptr::null_mut;
/// use voluntary_servitude::ffi::*;
///
/// unsafe {
/// # #[cfg(feature = "logs")] initialize_logger();
/// let vs = vs_new();
/// let data: i32 = 5;
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// let iter = vs_iter(vs);
/// assert_eq!(vs_destroy(vs), 0);
///
/// assert_eq!(*(vs_iter_next(iter) as *const i32), 5);
/// assert_eq!(vs_iter_destroy(iter), 0);
///
/// // Returns 1 on NULL pointer
/// assert_eq!(vs_destroy(null_mut()), 1);
/// }
/// ```
///
/// # C
///
/// ```c
/// #include<assert.h>
/// #include "../include/voluntary_servitude.h"
///
/// int main(int argc, char **argv) {
/// vs_t * vs = vs_new();
/// vs_iter_t * iter = vs_iter(vs);
/// const unsigned int data = 5;
/// assert(vs_append(vs, (void *) &data) == 0);
/// assert(vs_destroy(vs) == 0);
///
/// assert(*(unsigned int *) vs_iter_next(iter) == 5);
/// assert(vs_iter_destroy(vs) == 0);
///
/// // Returns 1 on NULL pointer
/// assert(vs_destroy(NULL) == 1);
/// return 0;
/// }
/// ```
#[no_mangle]
pub unsafe extern "C" fn vs_destroy(list: *mut VoluntaryServitude<*const c_void>) -> u8 {
null_check!(list, 1);
drop(Box::from_raw(list));
0
}
/// Obtains next element in iterator, returns NULL if there are no more elements
///
/// Returns NULL if pointer to [`VSIter`] is NULL
///
/// Warning: UB if pointer to [`VSIter`] is invalid
///
/// [`VSIter`]: ../struct.VSIter.html
///
/// # Rust
///
/// ```rust
/// use std::ptr::null_mut;
/// use voluntary_servitude::ffi::*;
///
/// unsafe {
/// # #[cfg(feature = "logs")] initialize_logger();
/// let vs = vs_new();
/// let data: i32 = 5;
///
/// let iter = vs_iter(vs);
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// assert!(vs_iter_next(iter).is_null());
/// assert_eq!(vs_iter_destroy(iter), 0);
///
/// let iter = vs_iter(vs);
/// assert_eq!(*(vs_iter_next(iter) as *const i32), 5);
/// assert!(vs_iter_next(iter).is_null());
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// assert!(vs_iter_next(iter).is_null());
///
/// assert_eq!(vs_iter_destroy(iter), 0);
/// assert_eq!(vs_destroy(vs), 0);
///
/// // Propagates NULL pointers
/// assert!(vs_iter_next(null_mut()).is_null());
/// }
/// ```
///
/// # C
///
/// ```c
/// #include<assert.h>
/// #include "../include/voluntary_servitude.h"
///
/// int main(int argc, char **argv) {
/// vs_t * vs = vs_new();
/// vs_iter_t * iter = vs_iter(vs);
/// const unsigned int data = 5;
/// assert(vs_append(vs, (void *) &data) == 0);
/// assert(vs_iter_next(iter) == NULL);
///
/// assert(vs_iter_destroy(iter) == 0);
/// iter = vs_iter(vs);
/// assert(*(unsigned int *) vs_iter_next(iter) == 5);
/// assert(vs_iter_next(iter) == NULL);
/// assert(vs_append(vs, (void *) &data) == 0);
///
/// assert(vs_iter_next(iter) == NULL);
/// assert(vs_iter_destroy(iter) == 0);
/// assert(vs_destroy(vs) == 0);
///
/// // Propagates NULL pointers
/// assert(vs_iter_next(NULL) == NULL);
/// return 0;
/// }
/// ```
#[no_mangle]
pub unsafe extern "C" fn vs_iter_next(iter: *mut VSIter<'_, *const c_void>) -> *const c_void {
null_check!(iter, null_mut());
match (*iter).next() {
Some(pointer) => *pointer,
None => null_mut(),
}
}
/// Returns total size of iterator, it may grow, but never decrease
///
/// Length won't increase after iterator is emptied (self.next() == None)
///
/// Returns 0 if pointer to [`VSIter`] is NULL
///
/// Warning: UB if pointer to [`VSIter`] is invalid
///
/// [`VSIter`]: ../struct.VSIter.html
///
/// # Rust
///
/// ```rust
/// use std::ptr::null_mut;
/// use voluntary_servitude::ffi::*;
///
/// unsafe {
/// # #[cfg(feature = "logs")] initialize_logger();
/// let vs = vs_new();
/// let data: i32 = 5;
/// let iter = vs_iter(vs);
/// assert_eq!(vs_len(vs), 0);
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// assert_eq!(vs_iter_destroy(iter), 0);
///
/// let iter = vs_iter(vs);
/// assert_eq!(vs_len(vs), 1);
/// assert_eq!(vs_iter_len(iter), 1);
///
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
/// assert_eq!(vs_len(vs), 4);
/// assert_eq!(vs_iter_len(iter), 4);
///
/// assert_eq!(vs_clear(vs), 0);
/// assert_eq!(vs_iter_len(iter), 4);
/// assert_eq!(vs_iter_destroy(iter), 0);
///
/// let iter = vs_iter(vs);
/// assert_eq!(vs_iter_len(iter), 0);
///
/// assert_eq!(vs_iter_destroy(iter), 0);
/// assert_eq!(vs_destroy(vs), 0);
///
/// // 0 length on NULL pointer
/// assert_eq!(vs_iter_len(null_mut()), 0);
/// }
/// ```
///
/// # C
///
/// ```c
/// #include<assert.h>
/// #include "../include/voluntary_servitude.h"
///
/// int main(int argc, char **argv) {
/// vs_t * vs = vs_new();
/// const unsigned int data = 5;
/// assert_eq!(vs_append(vs, &data as *const i32 as *const c_void), 0);
///
/// assert(vs_len(vs) == 1);
/// vs_iter_t * iter = vs_iter(vs);
/// assert(vs_iter_len(iter) == 1);
///
/// const unsigned int data = 5;
/// assert(vs_append(vs, (void *) &data) == 0);
/// assert(vs_append(vs, (void *) &data) == 0);
/// assert(vs_append(vs, (void *) &data) == 0);
/// assert(vs_len(vs) == 4);
/// assert(vs_iter_len(iter) == 4);
///
/// assert(vs_clear() == 0);
/// assert(vs_iter_len(iter) == 4);
///
/// assert(vs_iter_destroy(iter) == 0);
///
/// vs_iter_t * iter2 = vs_iter(vs);
/// assert(vs_iter_len(iter2) == 0);
/// assert(vs_iter_destroy(iter2) == 0);
/// assert(vs_destroy(vs) == 0);
///
/// // 0 length on NULL pointer
/// assert(vs_iter_len(NULL) == 0);
/// return 0;
/// }
/// ```
#[no_mangle]
pub unsafe extern "C" fn vs_iter_len(iter: *const VSIter<'_, *const c_void>) -> usize {
null_check!(iter, 0);
(*iter).len()
}
/// Returns current iterator index
///
/// Returns 0 if pointer to [`VSIter`] is NULL
///
/// Warning: UB if pointer to [`VSIter`] is invalid
///
/// [`VSIter`]: ../struct.VSIter.html
///
/// # Rust
///
/// ```rust
/// use std::ptr::null_mut;
/// use voluntary_servitude::ffi::*;
///
/// unsafe {
/// # #[cfg(feature = "logs")] initialize_logger();
/// let vs = vs_new();
/// let data: [i32; 3] = [4, 9, 8];
/// assert_eq!(vs_append(vs, &data[0] as *const i32 as *const c_void), 0);
/// assert_eq!(vs_append(vs, &data[1] as *const i32 as *const c_void), 0);
/// assert_eq!(vs_append(vs, &data[2] as *const i32 as *const c_void), 0);
///
/// let iter = vs_iter(vs);
/// assert_eq!(vs_iter_index(iter), 0);
/// assert_eq!(*(vs_iter_next(iter) as *const i32), 4);
/// assert_eq!(*(vs_iter_next(iter) as *const i32), 9);
/// assert_eq!(*(vs_iter_next(iter) as *const i32), 8);
/// assert_eq!(vs_iter_index(iter), 3);
/// assert!(vs_iter_next(iter).is_null());
/// assert_eq!(vs_iter_index(iter), vs_iter_len(iter));
///
/// assert_eq!(vs_iter_destroy(iter), 0);
/// assert_eq!(vs_destroy(vs), 0);
///
/// // 0 index on NULL pointer
/// assert_eq!(vs_iter_index(null_mut()), 0);
/// }
/// ```
///
/// # C
///
/// ```c
/// #include<assert.h>
/// #include "../include/voluntary_servitude.h"
///
/// int main(int argc, char **argv) {
/// vs_t * vs = vs_new();
/// const unsigned int data[3] = { 4, 9, 8 };
/// assert(vs_append(vs, (void *) data) == 0);
/// assert(vs_append(vs, (void *) (data + 1)) == 0);
/// assert(vs_append(vs, (void *) (data + 2)) == 0);
///
/// vs_iter_t * iter = vs_iter(vs);
/// assert(vs_iter_index(iter) == 0);
/// assert(*(unsigned int *) vs_iter_next(iter) == 4);
/// assert(*(unsigned int *) vs_iter_next(iter) == 9);
/// assert(*(unsigned int *) vs_iter_next(iter) == 8);
/// assert(vs_iter_index(iter) == 3);
/// assert(vs_iter_next(iter) == NULL);
/// assert(vs_iter_index(iter) == vs_iter_len(iter));
///
/// assert(vs_iter_destroy(iter) == 0);
/// assert(vs_destroy(vs) == 0);
///
/// // 0 index on NULL pointer
/// assert(vs_iter_index(NULL) == 0);
/// return 0;
/// }
/// ```
#[no_mangle]
pub unsafe extern "C" fn vs_iter_index(iter: *const VSIter<'_, *const c_void>) -> usize {
null_check!(iter, 0);
(*iter).index()
}
/// Free [`VSIter`] (can happen after [`VoluntaryServitude`]'s free)
///
/// Returns 1 if pointer to [`VoluntaryServitude`] is NULL
///
/// Returns 0 otherwise
///
/// Warning: UB if pointer to [`VSIter`] is invalid
///
/// [`VoluntaryServitude`]: ../struct.VoluntaryServitude.html
/// [`VSIter`]: ../struct.VSIter.html
///
/// # Rust
///
/// ```rust
/// use std::ptr::null_mut;
/// use voluntary_servitude::ffi::*;
///
/// unsafe {
/// # #[cfg(feature = "logs")] initialize_logger();
/// let vs = vs_new();
/// let iter = vs_iter(vs);
/// assert_eq!(vs_destroy(vs), 0);
/// assert_eq!(vs_iter_destroy(iter), 0);
///
/// // Returns 1 on NULL pointer
/// assert_eq!(vs_iter_destroy(null_mut()), 1);
/// }
/// ```
///
/// # C
///
/// ```c
/// #include<assert.h>
/// #include "../include/voluntary_servitude.h"
///
/// int main(int argc, char **argv) {
/// vs_t * vs = vs_new();
/// const unsigned int data[3] = { 4, 9, 8 };
/// assert(vs_append(vs, (void *) data) == 0);
/// assert(vs_append(vs, (void *) (data + 1)) == 0);
/// assert(vs_append(vs, (void *) (data + 2)) == 0);
///
/// vs_iter_t * iter = vs_iter(vs);
/// assert(vs_iter_len(iter) == 3);
/// assert(vs_iter_destry(iter) == 0);
///
/// assert(vs_destroy(vs) == 0);
///
/// // Returns 1 on NULL pointer
/// assert(vs_iter_destroy(NULL) == 1);
/// return 0;
/// }
/// ```
#[no_mangle]
pub unsafe extern "C" fn vs_iter_destroy(iter: *mut VSIter<'_, *const c_void>) -> u8 {
null_check!(iter, 1);
drop(Box::from_raw(iter));
0
}