path: root/src/llvm_kaleidoscope_rs/lib.rs.html

                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                  

<!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 `src/lib.rs`."><title>lib.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/SourceSerif4-Regular-46f98efaafac5295.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/FiraSans-Regular-018c141bf0843ffd.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/FiraSans-Medium-8f9a781e4970d388.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2"><link rel="stylesheet" href="../../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../../static.files/rustdoc-17e279919966e8e4.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="llvm_kaleidoscope_rs" data-themes="" data-resource-suffix="" data-rustdoc-version="1.75.0 (82e1608df 2023-12-21) (built from a source tarball)" data-channel="1.75.0" data-search-js="search-8fbf244ebcf71464.js" data-settings-js="settings-74424d7eec62a23e.js" ><script src="../../static.files/storage-fec3eaa3851e447d.js"></script><script defer src="../../static.files/src-script-3280b574d94e47b4.js"></script><script defer src="../../src-files.js"></script><script defer src="../../static.files/main-9dd44ab47b99a0fb.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-5d8b3c7633ad77ba.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-16x16-8b506e7a72182f1c.png"><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc src"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"></nav><main><nav class="sub"><form class="search-form"><span></span><input class="search-input" name="search" aria-label="Run search in the documentation" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../static.files/wheel-7b819b6101059cd0.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><div data-nosnippet><pre class="src-line-numbers"><a href="#1" id="1">1</a>
<a href="#2" id="2">2</a>
<a href="#3" id="3">3</a>
<a href="#4" id="4">4</a>
<a href="#5" id="5">5</a>
<a href="#6" id="6">6</a>
<a href="#7" id="7">7</a>
<a href="#8" id="8">8</a>
<a href="#9" id="9">9</a>
<a href="#10" id="10">10</a>
<a href="#11" id="11">11</a>
<a href="#12" id="12">12</a>
<a href="#13" id="13">13</a>
<a href="#14" id="14">14</a>
<a href="#15" id="15">15</a>
<a href="#16" id="16">16</a>
<a href="#17" id="17">17</a>
<a href="#18" id="18">18</a>
<a href="#19" id="19">19</a>
<a href="#20" id="20">20</a>
<a href="#21" id="21">21</a>
<a href="#22" id="22">22</a>
<a href="#23" id="23">23</a>
<a href="#24" id="24">24</a>
<a href="#25" id="25">25</a>
<a href="#26" id="26">26</a>
<a href="#27" id="27">27</a>
<a href="#28" id="28">28</a>
<a href="#29" id="29">29</a>
<a href="#30" id="30">30</a>
<a href="#31" id="31">31</a>
<a href="#32" id="32">32</a>
<a href="#33" id="33">33</a>
<a href="#34" id="34">34</a>
<a href="#35" id="35">35</a>
<a href="#36" id="36">36</a>
<a href="#37" id="37">37</a>
<a href="#38" id="38">38</a>
<a href="#39" id="39">39</a>
<a href="#40" id="40">40</a>
<a href="#41" id="41">41</a>
<a href="#42" id="42">42</a>
<a href="#43" id="43">43</a>
<a href="#44" id="44">44</a>
<a href="#45" id="45">45</a>
<a href="#46" id="46">46</a>
<a href="#47" id="47">47</a>
<a href="#48" id="48">48</a>
<a href="#49" id="49">49</a>
<a href="#50" id="50">50</a>
<a href="#51" id="51">51</a>
<a href="#52" id="52">52</a>
<a href="#53" id="53">53</a>
<a href="#54" id="54">54</a>
<a href="#55" id="55">55</a>
<a href="#56" id="56">56</a>
<a href="#57" id="57">57</a>
<a href="#58" id="58">58</a>
<a href="#59" id="59">59</a>
<a href="#60" id="60">60</a>
<a href="#61" id="61">61</a>
<a href="#62" id="62">62</a>
<a href="#63" id="63">63</a>
<a href="#64" id="64">64</a>
<a href="#65" id="65">65</a>
<a href="#66" id="66">66</a>
<a href="#67" id="67">67</a>
<a href="#68" id="68">68</a>
<a href="#69" id="69">69</a>
<a href="#70" id="70">70</a>
<a href="#71" id="71">71</a>
<a href="#72" id="72">72</a>
<a href="#73" id="73">73</a>
<a href="#74" id="74">74</a>
<a href="#75" id="75">75</a>
<a href="#76" id="76">76</a>
<a href="#77" id="77">77</a>
<a href="#78" id="78">78</a>
<a href="#79" id="79">79</a>
<a href="#80" id="80">80</a>
<a href="#81" id="81">81</a>
<a href="#82" id="82">82</a>
<a href="#83" id="83">83</a>
<a href="#84" id="84">84</a>
<a href="#85" id="85">85</a>
<a href="#86" id="86">86</a>
<a href="#87" id="87">87</a>
<a href="#88" id="88">88</a>
<a href="#89" id="89">89</a>
<a href="#90" id="90">90</a>
<a href="#91" id="91">91</a>
<a href="#92" id="92">92</a>
<a href="#93" id="93">93</a>
<a href="#94" id="94">94</a>
<a href="#95" id="95">95</a>
<a href="#96" id="96">96</a>
<a href="#97" id="97">97</a>
<a href="#98" id="98">98</a>
<a href="#99" id="99">99</a>
<a href="#100" id="100">100</a>
<a href="#101" id="101">101</a>
<a href="#102" id="102">102</a>
<a href="#103" id="103">103</a>
<a href="#104" id="104">104</a>
<a href="#105" id="105">105</a>
<a href="#106" id="106">106</a>
<a href="#107" id="107">107</a>
<a href="#108" id="108">108</a>
<a href="#109" id="109">109</a>
<a href="#110" id="110">110</a>
<a href="#111" id="111">111</a>
</pre></div><pre class="rust"><code><span class="kw">use </span>std::convert::TryFrom;

<span class="kw">pub mod </span>codegen;
<span class="kw">pub mod </span>lexer;
<span class="kw">pub mod </span>llvm;
<span class="kw">pub mod </span>parser;

<span class="doccomment">/// Fixed size of [`SmallCStr`] including the trailing `\0` byte.
</span><span class="kw">pub const </span>SMALL_STR_SIZE: usize = <span class="number">16</span>;

<span class="doccomment">/// Small C string on the stack with fixed size [`SMALL_STR_SIZE`].
///
/// This is specially crafted to interact with the LLVM C API and get rid of some heap allocations.
</span><span class="attr">#[derive(Debug, PartialEq)]
</span><span class="kw">pub struct </span>SmallCStr([u8; SMALL_STR_SIZE]);

<span class="kw">impl </span>SmallCStr {
    <span class="doccomment">/// Create a new C string from `src`.
    /// Returns [`None`] if `src` exceeds the fixed size or contains any `\0` bytes.
    </span><span class="kw">pub fn </span>new&lt;T: AsRef&lt;[u8]&gt;&gt;(src: <span class="kw-2">&amp;</span>T) -&gt; <span class="prelude-ty">Option</span>&lt;SmallCStr&gt; {
        <span class="kw">let </span>src = src.as_ref();
        <span class="kw">let </span>len = src.len();

        <span class="comment">// Check for \0 bytes.
        </span><span class="kw">let </span>contains_null = <span class="kw">unsafe </span>{ !libc::memchr(src.as_ptr().cast(), <span class="number">0</span>, len).is_null() };

        <span class="kw">if </span>contains_null || len &gt; SMALL_STR_SIZE - <span class="number">1 </span>{
            <span class="prelude-val">None
        </span>} <span class="kw">else </span>{
            <span class="kw">let </span><span class="kw-2">mut </span>dest = [<span class="number">0</span>; SMALL_STR_SIZE];
            dest[..len].copy_from_slice(src);
            <span class="prelude-val">Some</span>(SmallCStr(dest))
        }
    }

    <span class="doccomment">/// Return pointer to C string.
    </span><span class="kw">pub const fn </span>as_ptr(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="kw-2">*const </span>libc::c_char {
        <span class="self">self</span>.<span class="number">0</span>.as_ptr().cast()
    }
}

<span class="kw">impl </span>TryFrom&lt;<span class="kw-2">&amp;</span>str&gt; <span class="kw">for </span>SmallCStr {
    <span class="kw">type </span>Error = ();

    <span class="kw">fn </span>try_from(value: <span class="kw-2">&amp;</span>str) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>, <span class="self">Self</span>::Error&gt; {
        SmallCStr::new(<span class="kw-2">&amp;</span>value).ok_or(())
    }
}

<span class="doccomment">/// Either type, for APIs accepting two types.
</span><span class="kw">pub enum </span>Either&lt;A, B&gt; {
    A(A),
    B(B),
}

<span class="attr">#[cfg(test)]
</span><span class="kw">mod </span>test {
    <span class="kw">use super</span>::{SmallCStr, SMALL_STR_SIZE};
    <span class="kw">use </span>std::convert::TryInto;

    <span class="attr">#[test]
    </span><span class="kw">fn </span>test_create() {
        <span class="kw">let </span>src = <span class="string">&quot;\x30\x31\x32\x33&quot;</span>;
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src).unwrap();
        <span class="macro">assert_eq!</span>(<span class="kw-2">&amp;</span>scs.<span class="number">0</span>[..<span class="number">5</span>], <span class="kw-2">&amp;</span>[<span class="number">0x30</span>, <span class="number">0x31</span>, <span class="number">0x32</span>, <span class="number">0x33</span>, <span class="number">0x00</span>]);

        <span class="kw">let </span>src = <span class="string">b&quot;abcd1234&quot;</span>;
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src).unwrap();
        <span class="macro">assert_eq!</span>(
            <span class="kw-2">&amp;</span>scs.<span class="number">0</span>[..<span class="number">9</span>],
            <span class="kw-2">&amp;</span>[<span class="number">0x61</span>, <span class="number">0x62</span>, <span class="number">0x63</span>, <span class="number">0x64</span>, <span class="number">0x31</span>, <span class="number">0x32</span>, <span class="number">0x33</span>, <span class="number">0x34</span>, <span class="number">0x00</span>]
        );
    }

    <span class="attr">#[test]
    </span><span class="kw">fn </span>test_contain_null() {
        <span class="kw">let </span>src = <span class="string">&quot;\x30\x00\x32\x33&quot;</span>;
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src);
        <span class="macro">assert_eq!</span>(scs, <span class="prelude-val">None</span>);

        <span class="kw">let </span>src = <span class="string">&quot;\x30\x31\x32\x33\x00&quot;</span>;
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src);
        <span class="macro">assert_eq!</span>(scs, <span class="prelude-val">None</span>);
    }

    <span class="attr">#[test]
    </span><span class="kw">fn </span>test_too_large() {
        <span class="kw">let </span>src = (<span class="number">0</span>..SMALL_STR_SIZE).map(|<span class="kw">_</span>| <span class="string">&#39;a&#39;</span>).collect::&lt;String&gt;();
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src);
        <span class="macro">assert_eq!</span>(scs, <span class="prelude-val">None</span>);

        <span class="kw">let </span>src = (<span class="number">0</span>..SMALL_STR_SIZE + <span class="number">10</span>).map(|<span class="kw">_</span>| <span class="string">&#39;a&#39;</span>).collect::&lt;String&gt;();
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src);
        <span class="macro">assert_eq!</span>(scs, <span class="prelude-val">None</span>);
    }

    <span class="attr">#[test]
    </span><span class="kw">fn </span>test_try_into() {
        <span class="kw">let </span>src = <span class="string">&quot;\x30\x31\x32\x33&quot;</span>;
        <span class="kw">let </span>scs: <span class="prelude-ty">Result</span>&lt;SmallCStr, ()&gt; = src.try_into();
        <span class="macro">assert!</span>(scs.is_ok());

        <span class="kw">let </span>src = (<span class="number">0</span>..SMALL_STR_SIZE).map(|<span class="kw">_</span>| <span class="string">&#39;a&#39;</span>).collect::&lt;String&gt;();
        <span class="kw">let </span>scs: <span class="prelude-ty">Result</span>&lt;SmallCStr, ()&gt; = src.as_str().try_into();
        <span class="macro">assert!</span>(scs.is_err());

        <span class="kw">let </span>src = (<span class="number">0</span>..SMALL_STR_SIZE + <span class="number">10</span>).map(|<span class="kw">_</span>| <span class="string">&#39;a&#39;</span>).collect::&lt;String&gt;();
        <span class="kw">let </span>scs: <span class="prelude-ty">Result</span>&lt;SmallCStr, ()&gt; = src.as_str().try_into();
        <span class="macro">assert!</span>(scs.is_err());
    }
}
</code></pre></div></section></main></body></html>
<!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 `src/lib.rs`."><title>lib.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/SourceSerif4-Regular-46f98efaafac5295.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/FiraSans-Regular-018c141bf0843ffd.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/FiraSans-Medium-8f9a781e4970d388.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/SourceCodePro-Regular-562dcc5011b6de7d.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../static.files/SourceCodePro-Semibold-d899c5a5c4aeb14a.ttf.woff2"><link rel="stylesheet" href="../../static.files/normalize-76eba96aa4d2e634.css"><link rel="stylesheet" href="../../static.files/rustdoc-17e279919966e8e4.css"><meta name="rustdoc-vars" data-root-path="../../" data-static-root-path="../../static.files/" data-current-crate="llvm_kaleidoscope_rs" data-themes="" data-resource-suffix="" data-rustdoc-version="1.75.0 (82e1608df 2023-12-21) (built from a source tarball)" data-channel="1.75.0" data-search-js="search-8fbf244ebcf71464.js" data-settings-js="settings-74424d7eec62a23e.js" ><script src="../../static.files/storage-fec3eaa3851e447d.js"></script><script defer src="../../static.files/src-script-3280b574d94e47b4.js"></script><script defer src="../../src-files.js"></script><script defer src="../../static.files/main-9dd44ab47b99a0fb.js"></script><noscript><link rel="stylesheet" href="../../static.files/noscript-5d8b3c7633ad77ba.css"></noscript><link rel="alternate icon" type="image/png" href="../../static.files/favicon-16x16-8b506e7a72182f1c.png"><link rel="alternate icon" type="image/png" href="../../static.files/favicon-32x32-422f7d1d52889060.png"><link rel="icon" type="image/svg+xml" href="../../static.files/favicon-2c020d218678b618.svg"></head><body class="rustdoc src"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"></nav><main><nav class="sub"><form class="search-form"><span></span><input class="search-input" name="search" aria-label="Run search in the documentation" autocomplete="off" spellcheck="false" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"><div id="help-button" title="help" tabindex="-1"><a href="../../help.html">?</a></div><div id="settings-menu" tabindex="-1"><a href="../../settings.html" title="settings"><img width="22" height="22" alt="Change settings" src="../../static.files/wheel-7b819b6101059cd0.svg"></a></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><div data-nosnippet><pre class="src-line-numbers"><a href="#1" id="1">1</a>
<a href="#2" id="2">2</a>
<a href="#3" id="3">3</a>
<a href="#4" id="4">4</a>
<a href="#5" id="5">5</a>
<a href="#6" id="6">6</a>
<a href="#7" id="7">7</a>
<a href="#8" id="8">8</a>
<a href="#9" id="9">9</a>
<a href="#10" id="10">10</a>
<a href="#11" id="11">11</a>
<a href="#12" id="12">12</a>
<a href="#13" id="13">13</a>
<a href="#14" id="14">14</a>
<a href="#15" id="15">15</a>
<a href="#16" id="16">16</a>
<a href="#17" id="17">17</a>
<a href="#18" id="18">18</a>
<a href="#19" id="19">19</a>
<a href="#20" id="20">20</a>
<a href="#21" id="21">21</a>
<a href="#22" id="22">22</a>
<a href="#23" id="23">23</a>
<a href="#24" id="24">24</a>
<a href="#25" id="25">25</a>
<a href="#26" id="26">26</a>
<a href="#27" id="27">27</a>
<a href="#28" id="28">28</a>
<a href="#29" id="29">29</a>
<a href="#30" id="30">30</a>
<a href="#31" id="31">31</a>
<a href="#32" id="32">32</a>
<a href="#33" id="33">33</a>
<a href="#34" id="34">34</a>
<a href="#35" id="35">35</a>
<a href="#36" id="36">36</a>
<a href="#37" id="37">37</a>
<a href="#38" id="38">38</a>
<a href="#39" id="39">39</a>
<a href="#40" id="40">40</a>
<a href="#41" id="41">41</a>
<a href="#42" id="42">42</a>
<a href="#43" id="43">43</a>
<a href="#44" id="44">44</a>
<a href="#45" id="45">45</a>
<a href="#46" id="46">46</a>
<a href="#47" id="47">47</a>
<a href="#48" id="48">48</a>
<a href="#49" id="49">49</a>
<a href="#50" id="50">50</a>
<a href="#51" id="51">51</a>
<a href="#52" id="52">52</a>
<a href="#53" id="53">53</a>
<a href="#54" id="54">54</a>
<a href="#55" id="55">55</a>
<a href="#56" id="56">56</a>
<a href="#57" id="57">57</a>
<a href="#58" id="58">58</a>
<a href="#59" id="59">59</a>
<a href="#60" id="60">60</a>
<a href="#61" id="61">61</a>
<a href="#62" id="62">62</a>
<a href="#63" id="63">63</a>
<a href="#64" id="64">64</a>
<a href="#65" id="65">65</a>
<a href="#66" id="66">66</a>
<a href="#67" id="67">67</a>
<a href="#68" id="68">68</a>
<a href="#69" id="69">69</a>
<a href="#70" id="70">70</a>
<a href="#71" id="71">71</a>
<a href="#72" id="72">72</a>
<a href="#73" id="73">73</a>
<a href="#74" id="74">74</a>
<a href="#75" id="75">75</a>
<a href="#76" id="76">76</a>
<a href="#77" id="77">77</a>
<a href="#78" id="78">78</a>
<a href="#79" id="79">79</a>
<a href="#80" id="80">80</a>
<a href="#81" id="81">81</a>
<a href="#82" id="82">82</a>
<a href="#83" id="83">83</a>
<a href="#84" id="84">84</a>
<a href="#85" id="85">85</a>
<a href="#86" id="86">86</a>
<a href="#87" id="87">87</a>
<a href="#88" id="88">88</a>
<a href="#89" id="89">89</a>
<a href="#90" id="90">90</a>
<a href="#91" id="91">91</a>
<a href="#92" id="92">92</a>
<a href="#93" id="93">93</a>
<a href="#94" id="94">94</a>
<a href="#95" id="95">95</a>
<a href="#96" id="96">96</a>
<a href="#97" id="97">97</a>
<a href="#98" id="98">98</a>
<a href="#99" id="99">99</a>
<a href="#100" id="100">100</a>
<a href="#101" id="101">101</a>
<a href="#102" id="102">102</a>
<a href="#103" id="103">103</a>
<a href="#104" id="104">104</a>
<a href="#105" id="105">105</a>
<a href="#106" id="106">106</a>
<a href="#107" id="107">107</a>
<a href="#108" id="108">108</a>
<a href="#109" id="109">109</a>
<a href="#110" id="110">110</a>
<a href="#111" id="111">111</a>
</pre></div><pre class="rust"><code><span class="kw">use </span>std::convert::TryFrom;

<span class="kw">pub mod </span>codegen;
<span class="kw">pub mod </span>lexer;
<span class="kw">pub mod </span>llvm;
<span class="kw">pub mod </span>parser;

<span class="doccomment">/// Fixed size of [`SmallCStr`] including the trailing `\0` byte.
</span><span class="kw">pub const </span>SMALL_STR_SIZE: usize = <span class="number">16</span>;

<span class="doccomment">/// Small C string on the stack with fixed size [`SMALL_STR_SIZE`].
///
/// This is specially crafted to interact with the LLVM C API and get rid of some heap allocations.
</span><span class="attr">#[derive(Debug, PartialEq)]
</span><span class="kw">pub struct </span>SmallCStr([u8; SMALL_STR_SIZE]);

<span class="kw">impl </span>SmallCStr {
    <span class="doccomment">/// Create a new C string from `src`.
    /// Returns [`None`] if `src` exceeds the fixed size or contains any `\0` bytes.
    </span><span class="kw">pub fn </span>new&lt;T: AsRef&lt;[u8]&gt;&gt;(src: <span class="kw-2">&amp;</span>T) -&gt; <span class="prelude-ty">Option</span>&lt;SmallCStr&gt; {
        <span class="kw">let </span>src = src.as_ref();
        <span class="kw">let </span>len = src.len();

        <span class="comment">// Check for \0 bytes.
        </span><span class="kw">let </span>contains_null = <span class="kw">unsafe </span>{ !libc::memchr(src.as_ptr().cast(), <span class="number">0</span>, len).is_null() };

        <span class="kw">if </span>contains_null || len &gt; SMALL_STR_SIZE - <span class="number">1 </span>{
            <span class="prelude-val">None
        </span>} <span class="kw">else </span>{
            <span class="kw">let </span><span class="kw-2">mut </span>dest = [<span class="number">0</span>; SMALL_STR_SIZE];
            dest[..len].copy_from_slice(src);
            <span class="prelude-val">Some</span>(SmallCStr(dest))
        }
    }

    <span class="doccomment">/// Return pointer to C string.
    </span><span class="kw">pub const fn </span>as_ptr(<span class="kw-2">&amp;</span><span class="self">self</span>) -&gt; <span class="kw-2">*const </span>libc::c_char {
        <span class="self">self</span>.<span class="number">0</span>.as_ptr().cast()
    }
}

<span class="kw">impl </span>TryFrom&lt;<span class="kw-2">&amp;</span>str&gt; <span class="kw">for </span>SmallCStr {
    <span class="kw">type </span>Error = ();

    <span class="kw">fn </span>try_from(value: <span class="kw-2">&amp;</span>str) -&gt; <span class="prelude-ty">Result</span>&lt;<span class="self">Self</span>, <span class="self">Self</span>::Error&gt; {
        SmallCStr::new(<span class="kw-2">&amp;</span>value).ok_or(())
    }
}

<span class="doccomment">/// Either type, for APIs accepting two types.
</span><span class="kw">pub enum </span>Either&lt;A, B&gt; {
    A(A),
    B(B),
}

<span class="attr">#[cfg(test)]
</span><span class="kw">mod </span>test {
    <span class="kw">use super</span>::{SmallCStr, SMALL_STR_SIZE};
    <span class="kw">use </span>std::convert::TryInto;

    <span class="attr">#[test]
    </span><span class="kw">fn </span>test_create() {
        <span class="kw">let </span>src = <span class="string">&quot;\x30\x31\x32\x33&quot;</span>;
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src).unwrap();
        <span class="macro">assert_eq!</span>(<span class="kw-2">&amp;</span>scs.<span class="number">0</span>[..<span class="number">5</span>], <span class="kw-2">&amp;</span>[<span class="number">0x30</span>, <span class="number">0x31</span>, <span class="number">0x32</span>, <span class="number">0x33</span>, <span class="number">0x00</span>]);

        <span class="kw">let </span>src = <span class="string">b&quot;abcd1234&quot;</span>;
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src).unwrap();
        <span class="macro">assert_eq!</span>(
            <span class="kw-2">&amp;</span>scs.<span class="number">0</span>[..<span class="number">9</span>],
            <span class="kw-2">&amp;</span>[<span class="number">0x61</span>, <span class="number">0x62</span>, <span class="number">0x63</span>, <span class="number">0x64</span>, <span class="number">0x31</span>, <span class="number">0x32</span>, <span class="number">0x33</span>, <span class="number">0x34</span>, <span class="number">0x00</span>]
        );
    }

    <span class="attr">#[test]
    </span><span class="kw">fn </span>test_contain_null() {
        <span class="kw">let </span>src = <span class="string">&quot;\x30\x00\x32\x33&quot;</span>;
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src);
        <span class="macro">assert_eq!</span>(scs, <span class="prelude-val">None</span>);

        <span class="kw">let </span>src = <span class="string">&quot;\x30\x31\x32\x33\x00&quot;</span>;
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src);
        <span class="macro">assert_eq!</span>(scs, <span class="prelude-val">None</span>);
    }

    <span class="attr">#[test]
    </span><span class="kw">fn </span>test_too_large() {
        <span class="kw">let </span>src = (<span class="number">0</span>..SMALL_STR_SIZE).map(|<span class="kw">_</span>| <span class="string">&#39;a&#39;</span>).collect::&lt;String&gt;();
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src);
        <span class="macro">assert_eq!</span>(scs, <span class="prelude-val">None</span>);

        <span class="kw">let </span>src = (<span class="number">0</span>..SMALL_STR_SIZE + <span class="number">10</span>).map(|<span class="kw">_</span>| <span class="string">&#39;a&#39;</span>).collect::&lt;String&gt;();
        <span class="kw">let </span>scs = SmallCStr::new(<span class="kw-2">&amp;</span>src);
        <span class="macro">assert_eq!</span>(scs, <span class="prelude-val">None</span>);
    }

    <span class="attr">#[test]
    </span><span class="kw">fn </span>test_try_into() {
        <span class="kw">let </span>src = <span class="string">&quot;\x30\x31\x32\x33&quot;</span>;
        <span class="kw">let </span>scs: <span class="prelude-ty">Result</span>&lt;SmallCStr, ()&gt; = src.try_into();
        <span class="macro">assert!</span>(scs.is_ok());

        <span class="kw">let </span>src = (<span class="number">0</span>..SMALL_STR_SIZE).map(|<span class="kw">_</span>| <span class="string">&#39;a&#39;</span>).collect::&lt;String&gt;();
        <span class="kw">let </span>scs: <span class="prelude-ty">Result</span>&lt;SmallCStr, ()&gt; = src.as_str().try_into();
        <span class="macro">assert!</span>(scs.is_err());

        <span class="kw">let </span>src = (<span class="number">0</span>..SMALL_STR_SIZE + <span class="number">10</span>).map(|<span class="kw">_</span>| <span class="string">&#39;a&#39;</span>).collect::&lt;String&gt;();
        <span class="kw">let </span>scs: <span class="prelude-ty">Result</span>&lt;SmallCStr, ()&gt; = src.as_str().try_into();
        <span class="macro">assert!</span>(scs.is_err());
    }
}
</code></pre></div></section></main></body></html>