<!DOCTYPE html><html lang="en"><head><meta charset="utf-8"><meta name="viewport" content="width=device-width, initial-scale=1.0"><meta name="generator" content="rustdoc"><meta name="description" content="Source of the Rust file `/home/sangenya/.cargo/registry/src/github.com-1ecc6299db9ec823/safemem-0.2.0/src/lib.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>lib.rs - source</title><link rel="stylesheet" type="text/css" href="../../normalize.css"><link rel="stylesheet" type="text/css" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" type="text/css" href="../../light.css" id="themeStyle"><link rel="stylesheet" type="text/css" href="../../dark.css" disabled ><link rel="stylesheet" type="text/css" href="../../ayu.css" disabled ><script id="default-settings"></script><script src="../../storage.js"></script><script src="../../crates.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="icon" type="image/svg+xml" href="../../favicon.svg">
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</pre><pre class="rust">
<span class="doccomment">//! Safe wrappers for memory-accessing functions like `std::ptr::copy()`.</span>
<span class="kw">use</span> <span class="ident">std::ptr</span>;
<span class="macro">macro_rules!</span> <span class="ident">idx_check</span> (
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">slice</span>:<span class="ident">expr</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">idx</span>:<span class="ident">expr</span>) <span class="op">=</span><span class="op">></span> {
<span class="macro">assert!</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">idx</span> <span class="op"><</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">slice</span>.<span class="ident">len</span>(),
<span class="macro">concat!</span>(<span class="string">"`"</span>, <span class="macro">stringify!</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">idx</span>), <span class="string">"` ({}) out of bounds. Length: {}"</span>),
<span class="macro-nonterminal">$</span><span class="macro-nonterminal">idx</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">slice</span>.<span class="ident">len</span>());
}
);
<span class="macro">macro_rules!</span> <span class="ident">len_check</span> (
(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">slice</span>:<span class="ident">expr</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">start</span>:<span class="ident">ident</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">len</span>:<span class="ident">ident</span>) <span class="op">=</span><span class="op">></span> {
<span class="macro">assert!</span>(
<span class="macro-nonterminal">$</span><span class="macro-nonterminal">start</span>.<span class="ident">checked_add</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">len</span>)
.<span class="ident">expect</span>(<span class="macro">concat!</span>(<span class="string">"Overflow evaluating "</span>, <span class="macro">stringify!</span>(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">start</span> <span class="op">+</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">len</span>)))
<span class="op"><</span><span class="op">=</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">slice</span>.<span class="ident">len</span>(),
<span class="string">"Length {} starting at {} is out of bounds (slice len {})."</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">len</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">start</span>, <span class="macro-nonterminal">$</span><span class="macro-nonterminal">slice</span>.<span class="ident">len</span>()
)
}
);
<span class="doccomment">/// Copy `len` elements from `src_idx` to `dest_idx`. Ranges may overlap.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// Safe wrapper for `memmove()`/`std::ptr::copy()`.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ###Panics</span>
<span class="doccomment">/// * If either `src_idx` or `dest_idx` are out of bounds, or if either of these plus `len` is out of</span>
<span class="doccomment">/// bounds.</span>
<span class="doccomment">/// * If `src_idx + len` or `dest_idx + len` overflows.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">copy_over</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Copy</span><span class="op">></span>(<span class="ident">slice</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="ident">T</span>], <span class="ident">src_idx</span>: <span class="ident">usize</span>, <span class="ident">dest_idx</span>: <span class="ident">usize</span>, <span class="ident">len</span>: <span class="ident">usize</span>) {
<span class="kw">if</span> <span class="ident">slice</span>.<span class="ident">len</span>() <span class="op">=</span><span class="op">=</span> <span class="number">0</span> { <span class="kw">return</span>; }
<span class="macro">idx_check!</span>(<span class="ident">slice</span>, <span class="ident">src_idx</span>);
<span class="macro">idx_check!</span>(<span class="ident">slice</span>, <span class="ident">dest_idx</span>);
<span class="macro">len_check!</span>(<span class="ident">slice</span>, <span class="ident">src_idx</span>, <span class="ident">len</span>);
<span class="macro">len_check!</span>(<span class="ident">slice</span>, <span class="ident">dest_idx</span>, <span class="ident">len</span>);
<span class="kw">let</span> <span class="ident">src_ptr</span>: <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">T</span> <span class="op">=</span> <span class="kw-2">&</span><span class="ident">slice</span>[<span class="ident">src_idx</span>];
<span class="kw">let</span> <span class="ident">dest_ptr</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">T</span> <span class="op">=</span> <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">slice</span>[<span class="ident">dest_idx</span>];
<span class="kw">unsafe</span> {
<span class="ident">ptr::copy</span>(<span class="ident">src_ptr</span>, <span class="ident">dest_ptr</span>, <span class="ident">len</span>);
}
}
<span class="doccomment">/// Safe wrapper for `std::ptr::write_bytes()`/`memset()`.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">write_bytes</span>(<span class="ident">slice</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> [<span class="ident">u8</span>], <span class="ident">byte</span>: <span class="ident">u8</span>) {
<span class="kw">unsafe</span> {
<span class="ident">ptr::write_bytes</span>(<span class="ident">slice</span>.<span class="ident">as_mut_ptr</span>(), <span class="ident">byte</span>, <span class="ident">slice</span>.<span class="ident">len</span>());
}
}
<span class="doccomment">/// Prepend `elems` to `vec`, resizing if necessary.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// ###Panics</span>
<span class="doccomment">/// If `vec.len() + elems.len()` overflows.</span>
<span class="kw">pub</span> <span class="kw">fn</span> <span class="ident">prepend</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">Copy</span><span class="op">></span>(<span class="ident">elems</span>: <span class="kw-2">&</span>[<span class="ident">T</span>], <span class="ident">vec</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">Vec</span><span class="op"><</span><span class="ident">T</span><span class="op">></span>) {
<span class="comment">// Our overflow check occurs here, no need to do it ourselves.</span>
<span class="ident">vec</span>.<span class="ident">reserve</span>(<span class="ident">elems</span>.<span class="ident">len</span>());
<span class="kw">let</span> <span class="ident">old_len</span> <span class="op">=</span> <span class="ident">vec</span>.<span class="ident">len</span>();
<span class="kw">let</span> <span class="ident">new_len</span> <span class="op">=</span> <span class="ident">old_len</span> <span class="op">+</span> <span class="ident">elems</span>.<span class="ident">len</span>();
<span class="kw">unsafe</span> {
<span class="ident">vec</span>.<span class="ident">set_len</span>(<span class="ident">new_len</span>);
}
<span class="comment">// Move the old elements down to the end.</span>
<span class="kw">if</span> <span class="ident">old_len</span> <span class="op">></span> <span class="number">0</span> {
<span class="ident">copy_over</span>(<span class="ident">vec</span>, <span class="number">0</span>, <span class="ident">elems</span>.<span class="ident">len</span>(), <span class="ident">old_len</span>);
}
<span class="ident">vec</span>[..<span class="ident">elems</span>.<span class="ident">len</span>()].<span class="ident">copy_from_slice</span>(<span class="ident">elems</span>);
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">test</span>)]</span>
<span class="kw">mod</span> <span class="ident">tests</span> {
<span class="kw">use</span> <span class="kw">super</span>::<span class="kw-2">*</span>;
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="attribute">#[<span class="ident">should_panic</span>]</span>
<span class="kw">fn</span> <span class="ident">bounds_check</span>() {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">arr</span> <span class="op">=</span> [<span class="number">0i32</span>, <span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>];
<span class="ident">copy_over</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">arr</span>, <span class="number">2</span>, <span class="number">1</span>, <span class="number">7</span>);
}
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">copy_empty</span>() {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">arr</span>: [<span class="ident">i32</span>; <span class="number">0</span>] <span class="op">=</span> [];
<span class="ident">copy_over</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">arr</span>, <span class="number">0</span>, <span class="number">0</span>, <span class="number">0</span>);
}
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">prepend_empty</span>() {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">vec</span>: <span class="ident">Vec</span><span class="op"><</span><span class="ident">i32</span><span class="op">></span> <span class="op">=</span> <span class="macro">vec!</span>[];
<span class="ident">prepend</span>(<span class="kw-2">&</span>[<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>], <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">vec</span>);
}
<span class="attribute">#[<span class="ident">test</span>]</span>
<span class="kw">fn</span> <span class="ident">prepend_i32</span>() {
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">vec</span> <span class="op">=</span> <span class="macro">vec!</span>[<span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>];
<span class="ident">prepend</span>(<span class="kw-2">&</span>[<span class="number">1</span>, <span class="number">2</span>], <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">vec</span>);
<span class="macro">assert_eq!</span>(<span class="ident">vec</span>, <span class="kw-2">&</span>[<span class="number">1</span>, <span class="number">2</span>, <span class="number">3</span>, <span class="number">4</span>, <span class="number">5</span>]);
}
}
</pre></div>
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