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</pre><div class="example-wrap"><pre class="rust ">
<span class="attribute">#![<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">""</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.30.0"</span>)]</span>
<span class="attribute">#![<span class="ident">allow</span>(<span class="ident">non_camel_case_types</span>)]</span>
<span class="doccomment">//! Utilities related to FFI bindings.</span>
<span class="kw">use</span> ::<span class="ident">fmt</span>;
<span class="doccomment">/// Equivalent to C's `void` type when used as a [pointer].</span>
<span class="doccomment">///</span>
<span class="doccomment">/// In essence, `*const c_void` is equivalent to C's `const void*`</span>
<span class="doccomment">/// and `*mut c_void` is equivalent to C's `void*`. That said, this is</span>
<span class="doccomment">/// *not* the same as C's `void` return type, which is Rust's `()` type.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// To model pointers to opaque types in FFI, until `extern type` is</span>
<span class="doccomment">/// stabilized, it is recommended to use a newtype wrapper around an empty</span>
<span class="doccomment">/// byte array. See the [Nomicon] for details.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [pointer]: ../../std/primitive.pointer.html</span>
<span class="doccomment">/// [Nomicon]: https://doc.rust-lang.org/nomicon/ffi.html#representing-opaque-structs</span>
<span class="comment">// N.B., for LLVM to recognize the void pointer type and by extension</span>
<span class="comment">// functions like malloc(), we need to have it represented as i8* in</span>
<span class="comment">// LLVM bitcode. The enum used here ensures this and prevents misuse</span>
<span class="comment">// of the "raw" type by only having private variants. We need two</span>
<span class="comment">// variants, because the compiler complains about the repr attribute</span>
<span class="comment">// otherwise and we need at least one variant as otherwise the enum</span>
<span class="comment">// would be uninhabited and at least dereferencing such pointers would</span>
<span class="comment">// be UB.</span>
<span class="attribute">#[<span class="ident">repr</span>(<span class="ident">u8</span>)]</span>
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"raw_os"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.1.0"</span>)]</span>
<span class="kw">pub</span> <span class="kw">enum</span> <span class="ident">c_void</span> {
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_void_variant"</span>, <span class="ident">reason</span> <span class="op">=</span> <span class="string">"temporary implementation detail"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"0"</span>)]</span>
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">hidden</span>)]</span> <span class="ident">__variant1</span>,
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_void_variant"</span>, <span class="ident">reason</span> <span class="op">=</span> <span class="string">"temporary implementation detail"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"0"</span>)]</span>
<span class="attribute">#[<span class="ident">doc</span>(<span class="ident">hidden</span>)]</span> <span class="ident">__variant2</span>,
}
<span class="attribute">#[<span class="ident">stable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"std_debug"</span>, <span class="ident">since</span> <span class="op">=</span> <span class="string">"1.16.0"</span>)]</span>
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">c_void</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="ident">f</span>.<span class="ident">pad</span>(<span class="string">"c_void"</span>)
}
}
<span class="doccomment">/// Basic implementation of a `va_list`.</span>
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">any</span>(<span class="ident">all</span>(<span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>), <span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"powerpc"</span>),
<span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86_64"</span>)),
<span class="ident">all</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">"ios"</span>),
<span class="ident">windows</span>))]</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="kw">extern</span> {
<span class="kw">type</span> <span class="ident">VaListImpl</span>;
}
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">any</span>(<span class="ident">all</span>(<span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>), <span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"powerpc"</span>),
<span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86_64"</span>)),
<span class="ident">all</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">"ios"</span>),
<span class="ident">windows</span>))]</span>
<span class="kw">impl</span> <span class="ident">fmt</span>::<span class="ident">Debug</span> <span class="kw">for</span> <span class="ident">VaListImpl</span> {
<span class="kw">fn</span> <span class="ident">fmt</span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">fmt</span>::<span class="ident">Formatter</span>) <span class="op">-></span> <span class="ident">fmt</span>::<span class="prelude-ty">Result</span> {
<span class="macro">write</span><span class="macro">!</span>(<span class="ident">f</span>, <span class="string">"va_list* {:p}"</span>, <span class="self">self</span>)
}
}
<span class="doccomment">/// AArch64 ABI implementation of a `va_list`. See the</span>
<span class="doccomment">/// [AArch64 Procedure Call Standard] for more details.</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [AArch64 Procedure Call Standard]:</span>
<span class="doccomment">/// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0055b/IHI0055B_aapcs64.pdf</span>
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">all</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">not</span>(<span class="ident">target_os</span> <span class="op">=</span> <span class="string">"ios"</span>), <span class="ident">not</span>(<span class="ident">windows</span>)))]</span>
<span class="attribute">#[<span class="ident">repr</span>(<span class="ident">C</span>)]</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="kw">struct</span> <span class="ident">VaListImpl</span> {
<span class="ident">stack</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>,
<span class="ident">gr_top</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>,
<span class="ident">vr_top</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>,
<span class="ident">gr_offs</span>: <span class="ident">i32</span>,
<span class="ident">vr_offs</span>: <span class="ident">i32</span>,
}
<span class="doccomment">/// PowerPC ABI implementation of a `va_list`.</span>
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">all</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"powerpc"</span>, <span class="ident">not</span>(<span class="ident">windows</span>)))]</span>
<span class="attribute">#[<span class="ident">repr</span>(<span class="ident">C</span>)]</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="kw">struct</span> <span class="ident">VaListImpl</span> {
<span class="ident">gpr</span>: <span class="ident">u8</span>,
<span class="ident">fpr</span>: <span class="ident">u8</span>,
<span class="ident">reserved</span>: <span class="ident">u16</span>,
<span class="ident">overflow_arg_area</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>,
<span class="ident">reg_save_area</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>,
}
<span class="doccomment">/// x86_64 ABI implementation of a `va_list`.</span>
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">all</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86_64"</span>, <span class="ident">not</span>(<span class="ident">windows</span>)))]</span>
<span class="attribute">#[<span class="ident">repr</span>(<span class="ident">C</span>)]</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="kw">struct</span> <span class="ident">VaListImpl</span> {
<span class="ident">gp_offset</span>: <span class="ident">i32</span>,
<span class="ident">fp_offset</span>: <span class="ident">i32</span>,
<span class="ident">overflow_arg_area</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>,
<span class="ident">reg_save_area</span>: <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">c_void</span>,
}
<span class="doccomment">/// A wrapper for a `va_list`</span>
<span class="attribute">#[<span class="ident">lang</span> <span class="op">=</span> <span class="string">"va_list"</span>]</span>
<span class="attribute">#[<span class="ident">derive</span>(<span class="ident">Debug</span>)]</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="attribute">#[<span class="ident">repr</span>(<span class="ident">transparent</span>)]</span>
<span class="kw">pub</span> <span class="kw">struct</span> <span class="ident">VaList</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span>(<span class="kw-2">&</span><span class="lifetime">'a</span> <span class="kw-2">mut</span> <span class="ident">VaListImpl</span>);
<span class="comment">// The VaArgSafe trait needs to be used in public interfaces, however, the trait</span>
<span class="comment">// itself must not be allowed to be used outside this module. Allowing users to</span>
<span class="comment">// implement the trait for a new type (thereby allowing the va_arg intrinsic to</span>
<span class="comment">// be used on a new type) is likely to cause undefined behavior.</span>
<span class="comment">//</span>
<span class="comment">// FIXME(dlrobertson): In order to use the VaArgSafe trait in a public interface</span>
<span class="comment">// but also ensure it cannot be used elsewhere, the trait needs to be public</span>
<span class="comment">// within a private module. Once RFC 2145 has been implemented look into</span>
<span class="comment">// improving this.</span>
<span class="kw">mod</span> <span class="ident">sealed_trait</span> {
<span class="doccomment">/// Trait which whitelists the allowed types to be used with [VaList::arg]</span>
<span class="doccomment">///</span>
<span class="doccomment">/// [VaList::va_arg]: struct.VaList.html#method.arg</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="kw">pub</span> <span class="kw">trait</span> <span class="ident">VaArgSafe</span> {}
}
<span class="macro">macro_rules</span><span class="macro">!</span> <span class="ident">impl_va_arg_safe</span> {
($(<span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span>:<span class="ident">ty</span>),<span class="op">+</span>) <span class="op">=></span> {
$(
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="kw">impl</span> <span class="ident">sealed_trait</span>::<span class="ident">VaArgSafe</span> <span class="kw">for</span> <span class="macro-nonterminal">$</span><span class="macro-nonterminal">t</span> {}
)<span class="op">+</span>
}
}
<span class="macro">impl_va_arg_safe</span><span class="macro">!</span>{<span class="ident">i8</span>, <span class="ident">i16</span>, <span class="ident">i32</span>, <span class="ident">i64</span>, <span class="ident">usize</span>}
<span class="macro">impl_va_arg_safe</span><span class="macro">!</span>{<span class="ident">u8</span>, <span class="ident">u16</span>, <span class="ident">u32</span>, <span class="ident">u64</span>, <span class="ident">isize</span>}
<span class="macro">impl_va_arg_safe</span><span class="macro">!</span>{<span class="ident">f64</span>}
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">sealed_trait</span>::<span class="ident">VaArgSafe</span> <span class="kw">for</span> <span class="kw-2">*</span><span class="kw-2">mut</span> <span class="ident">T</span> {}
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="kw">impl</span><span class="op"><</span><span class="ident">T</span><span class="op">></span> <span class="ident">sealed_trait</span>::<span class="ident">VaArgSafe</span> <span class="kw">for</span> <span class="kw-2">*</span><span class="kw">const</span> <span class="ident">T</span> {}
<span class="kw">impl</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> <span class="ident">VaList</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span> {
<span class="doccomment">/// Advance to the next arg.</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">arg</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">sealed_trait</span>::<span class="ident">VaArgSafe</span><span class="op">></span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="self">self</span>) <span class="op">-></span> <span class="ident">T</span> {
<span class="ident">va_arg</span>(<span class="self">self</span>)
}
<span class="doccomment">/// Copies the `va_list` at the current location.</span>
<span class="attribute">#[<span class="ident">unstable</span>(<span class="ident">feature</span> <span class="op">=</span> <span class="string">"c_variadic"</span>,
<span class="ident">reason</span> <span class="op">=</span> <span class="string">"the `c_variadic` feature has not been properly tested on \
all supported platforms"</span>,
<span class="ident">issue</span> <span class="op">=</span> <span class="string">"44930"</span>)]</span>
<span class="kw">pub</span> <span class="kw">unsafe</span> <span class="kw">fn</span> <span class="ident">with_copy</span><span class="op"><</span><span class="ident">F</span>, <span class="ident">R</span><span class="op">></span>(<span class="kw-2">&</span><span class="self">self</span>, <span class="ident">f</span>: <span class="ident">F</span>) <span class="op">-></span> <span class="ident">R</span>
<span class="kw">where</span> <span class="ident">F</span>: <span class="kw">for</span><span class="op"><</span><span class="lifetime">'copy</span><span class="op">></span> <span class="ident">FnOnce</span>(<span class="ident">VaList</span><span class="op"><</span><span class="lifetime">'copy</span><span class="op">></span>) <span class="op">-></span> <span class="ident">R</span> {
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">any</span>(<span class="ident">all</span>(<span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>), <span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"powerpc"</span>),
<span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86_64"</span>)),
<span class="ident">all</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">"ios"</span>),
<span class="ident">windows</span>))]</span>
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">ap</span> <span class="op">=</span> <span class="ident">va_copy</span>(<span class="self">self</span>);
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">all</span>(<span class="ident">any</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"powerpc"</span>, <span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86_64"</span>),
<span class="ident">not</span>(<span class="ident">windows</span>), <span class="ident">not</span>(<span class="ident">all</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">"ios"</span>))))]</span>
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">ap_inner</span> <span class="op">=</span> <span class="ident">va_copy</span>(<span class="self">self</span>);
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">all</span>(<span class="ident">any</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"powerpc"</span>, <span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86_64"</span>),
<span class="ident">not</span>(<span class="ident">windows</span>), <span class="ident">not</span>(<span class="ident">all</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">"ios"</span>))))]</span>
<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">ap</span> <span class="op">=</span> <span class="ident">VaList</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">ap_inner</span>);
<span class="kw">let</span> <span class="ident">ret</span> <span class="op">=</span> <span class="ident">f</span>(<span class="ident">VaList</span>(<span class="ident">ap</span>.<span class="number">0</span>));
<span class="ident">va_end</span>(<span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">ap</span>);
<span class="ident">ret</span>
}
}
<span class="kw">extern</span> <span class="string">"rust-intrinsic"</span> {
<span class="doccomment">/// Destroy the arglist `ap` after initialization with `va_start` or</span>
<span class="doccomment">/// `va_copy`.</span>
<span class="kw">fn</span> <span class="ident">va_end</span>(<span class="ident">ap</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">VaList</span>);
<span class="doccomment">/// Copies the current location of arglist `src` to the arglist `dst`.</span>
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">any</span>(<span class="ident">all</span>(<span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>), <span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"powerpc"</span>),
<span class="ident">not</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86_64"</span>)),
<span class="ident">all</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">"ios"</span>),
<span class="ident">windows</span>))]</span>
<span class="kw">fn</span> <span class="ident">va_copy</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span>(<span class="ident">src</span>: <span class="kw-2">&</span><span class="ident">VaList</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span>) <span class="op">-></span> <span class="ident">VaList</span><span class="op"><</span><span class="lifetime">'a</span><span class="op">></span>;
<span class="attribute">#[<span class="ident">cfg</span>(<span class="ident">all</span>(<span class="ident">any</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"powerpc"</span>, <span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"x86_64"</span>),
<span class="ident">not</span>(<span class="ident">windows</span>), <span class="ident">not</span>(<span class="ident">all</span>(<span class="ident">target_arch</span> <span class="op">=</span> <span class="string">"aarch64"</span>, <span class="ident">target_os</span> <span class="op">=</span> <span class="string">"ios"</span>))))]</span>
<span class="kw">fn</span> <span class="ident">va_copy</span>(<span class="ident">src</span>: <span class="kw-2">&</span><span class="ident">VaList</span>) <span class="op">-></span> <span class="ident">VaListImpl</span>;
<span class="doccomment">/// Loads an argument of type `T` from the `va_list` `ap` and increment the</span>
<span class="doccomment">/// argument `ap` points to.</span>
<span class="kw">fn</span> <span class="ident">va_arg</span><span class="op"><</span><span class="ident">T</span>: <span class="ident">sealed_trait</span>::<span class="ident">VaArgSafe</span><span class="op">></span>(<span class="ident">ap</span>: <span class="kw-2">&</span><span class="kw-2">mut</span> <span class="ident">VaList</span>) <span class="op">-></span> <span class="ident">T</span>;
}
</pre></div>
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