<style> body { margin: 0; } pre { color: #DCDCCC; background: #3F3F3F; font-size: 22px; padding: 0.4em; } .lifetime { color: #DFAF8F; font-style: italic; } .label { color: #DFAF8F; font-style: italic; } .comment { color: #7F9F7F; } .documentation { color: #629755; } .injected { opacity: 0.65 ; } .struct, .enum { color: #7CB8BB; } .enum_variant { color: #BDE0F3; } .string_literal { color: #CC9393; } .field { color: #94BFF3; } .function { color: #93E0E3; } .function.unsafe { color: #BC8383; } .operator.unsafe { color: #BC8383; } .parameter { color: #94BFF3; } .text { color: #DCDCCC; } .type { color: #7CB8BB; } .builtin_type { color: #8CD0D3; } .type_param { color: #DFAF8F; } .attribute { color: #94BFF3; } .numeric_literal { color: #BFEBBF; } .bool_literal { color: #BFE6EB; } .macro { color: #94BFF3; } .module { color: #AFD8AF; } .value_param { color: #DCDCCC; } .variable { color: #DCDCCC; } .format_specifier { color: #CC696B; } .mutable { text-decoration: underline; } .escape_sequence { color: #94BFF3; } .keyword { color: #F0DFAF; font-weight: bold; } .keyword.unsafe { color: #BC8383; font-weight: bold; } .control { font-style: italic; } .unresolved_reference { color: #FC5555; text-decoration: wavy underline; } </style> <pre><code><span class="keyword unsafe">unsafe</span> <span class="keyword">fn</span> <span class="function declaration unsafe">unsafe_fn</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span> <span class="keyword">union</span> <span class="union declaration">Union</span> <span class="brace">{</span> <span class="field declaration">a</span><span class="colon">:</span> <span class="builtin_type">u32</span><span class="comma">,</span> <span class="field declaration">b</span><span class="colon">:</span> <span class="builtin_type">f32</span><span class="comma">,</span> <span class="brace">}</span> <span class="keyword">struct</span> <span class="struct declaration">HasUnsafeFn</span><span class="semicolon">;</span> <span class="keyword">impl</span> <span class="struct">HasUnsafeFn</span> <span class="brace">{</span> <span class="keyword unsafe">unsafe</span> <span class="keyword">fn</span> <span class="function declaration associated unsafe">unsafe_method</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span> <span class="brace">}</span> <span class="keyword">struct</span> <span class="struct declaration">TypeForStaticMut</span> <span class="brace">{</span> <span class="field declaration">a</span><span class="colon">:</span> <span class="builtin_type">u8</span> <span class="brace">}</span> <span class="keyword">static</span> <span class="keyword">mut</span> <span class="static declaration mutable unsafe">global_mut</span><span class="colon">:</span> <span class="struct">TypeForStaticMut</span> <span class="operator">=</span> <span class="struct">TypeForStaticMut</span> <span class="brace">{</span> <span class="field">a</span><span class="colon">:</span> <span class="numeric_literal">0</span> <span class="brace">}</span><span class="semicolon">;</span> <span class="attribute attribute">#</span><span class="attribute attribute">[</span><span class="function attribute">repr</span><span class="parenthesis attribute">(</span><span class="attribute attribute">packed</span><span class="parenthesis attribute">)</span><span class="attribute attribute">]</span> <span class="keyword">struct</span> <span class="struct declaration">Packed</span> <span class="brace">{</span> <span class="field declaration">a</span><span class="colon">:</span> <span class="builtin_type">u16</span><span class="comma">,</span> <span class="brace">}</span> <span class="keyword">trait</span> <span class="trait declaration">DoTheAutoref</span> <span class="brace">{</span> <span class="keyword">fn</span> <span class="function declaration associated">calls_autoref</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span><span class="semicolon">;</span> <span class="brace">}</span> <span class="keyword">impl</span> <span class="trait">DoTheAutoref</span> <span class="keyword">for</span> <span class="builtin_type">u16</span> <span class="brace">{</span> <span class="keyword">fn</span> <span class="function declaration associated">calls_autoref</span><span class="parenthesis">(</span><span class="operator">&</span><span class="self_keyword declaration">self</span><span class="parenthesis">)</span> <span class="brace">{</span><span class="brace">}</span> <span class="brace">}</span> <span class="keyword">fn</span> <span class="function declaration">main</span><span class="parenthesis">(</span><span class="parenthesis">)</span> <span class="brace">{</span> <span class="keyword">let</span> <span class="variable declaration">x</span> <span class="operator">=</span> <span class="operator">&</span><span class="numeric_literal">5</span> <span class="keyword">as</span> <span class="keyword">*</span><span class="keyword">const</span> <span class="punctuation">_</span> <span class="keyword">as</span> <span class="keyword">*</span><span class="keyword">const</span> <span class="builtin_type">usize</span><span class="semicolon">;</span> <span class="keyword">let</span> <span class="variable declaration">u</span> <span class="operator">=</span> <span class="union">Union</span> <span class="brace">{</span> <span class="field">b</span><span class="colon">:</span> <span class="numeric_literal">0</span> <span class="brace">}</span><span class="semicolon">;</span> <span class="keyword unsafe">unsafe</span> <span class="brace">{</span> <span class="comment">// unsafe fn and method calls</span> <span class="function unsafe">unsafe_fn</span><span class="parenthesis">(</span><span class="parenthesis">)</span><span class="semicolon">;</span> <span class="keyword">let</span> <span class="variable declaration">b</span> <span class="operator">=</span> <span class="variable">u</span><span class="operator">.</span><span class="field unsafe">b</span><span class="semicolon">;</span> <span class="keyword control">match</span> <span class="variable">u</span> <span class="brace">{</span> <span class="union">Union</span> <span class="brace">{</span> <span class="field unsafe">b</span><span class="colon">:</span> <span class="numeric_literal">0</span> <span class="brace">}</span> <span class="operator">=></span> <span class="parenthesis">(</span><span class="parenthesis">)</span><span class="comma">,</span> <span class="union">Union</span> <span class="brace">{</span> <span class="field unsafe">a</span> <span class="brace">}</span> <span class="operator">=></span> <span class="parenthesis">(</span><span class="parenthesis">)</span><span class="comma">,</span> <span class="brace">}</span> <span class="struct">HasUnsafeFn</span><span class="operator">.</span><span class="function associated unsafe">unsafe_method</span><span class="parenthesis">(</span><span class="parenthesis">)</span><span class="semicolon">;</span> <span class="comment">// unsafe deref</span> <span class="keyword">let</span> <span class="variable declaration">y</span> <span class="operator">=</span> <span class="operator unsafe">*</span><span class="variable">x</span><span class="semicolon">;</span> <span class="comment">// unsafe access to a static mut</span> <span class="keyword">let</span> <span class="variable declaration">a</span> <span class="operator">=</span> <span class="static mutable unsafe">global_mut</span><span class="operator">.</span><span class="field">a</span><span class="semicolon">;</span> <span class="comment">// unsafe ref of packed fields</span> <span class="keyword">let</span> <span class="variable declaration">packed</span> <span class="operator">=</span> <span class="struct">Packed</span> <span class="brace">{</span> <span class="field">a</span><span class="colon">:</span> <span class="numeric_literal">0</span> <span class="brace">}</span><span class="semicolon">;</span> <span class="keyword">let</span> <span class="variable declaration">a</span> <span class="operator">=</span> <span class="operator unsafe">&</span><span class="variable">packed</span><span class="operator">.</span><span class="field">a</span><span class="semicolon">;</span> <span class="keyword">let</span> <span class="keyword unsafe">ref</span> <span class="variable declaration">a</span> <span class="operator">=</span> <span class="variable">packed</span><span class="operator">.</span><span class="field">a</span><span class="semicolon">;</span> <span class="keyword">let</span> <span class="struct">Packed</span> <span class="brace">{</span> <span class="keyword unsafe">ref</span> <span class="field">a</span> <span class="brace">}</span> <span class="operator">=</span> <span class="variable">packed</span><span class="semicolon">;</span> <span class="keyword">let</span> <span class="struct">Packed</span> <span class="brace">{</span> <span class="field">a</span><span class="colon">:</span> <span class="keyword unsafe">ref</span> <span class="variable declaration">_a</span> <span class="brace">}</span> <span class="operator">=</span> <span class="variable">packed</span><span class="semicolon">;</span> <span class="comment">// unsafe auto ref of packed field</span> <span class="variable">packed</span><span class="operator">.</span><span class="field">a</span><span class="operator">.</span><span class="function associated unsafe">calls_autoref</span><span class="parenthesis">(</span><span class="parenthesis">)</span><span class="semicolon">;</span> <span class="brace">}</span> <span class="brace">}</span></code></pre>