| <!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 `/root/.cargo/registry/src/github.com-1ecc6299db9ec823/anyhow-1.0.71/src/context.rs`."><meta name="keywords" content="rust, rustlang, rust-lang"><title>context.rs - source</title><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Regular.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../FiraSans-Medium.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Regular.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceSerif4-Bold.ttf.woff2"><link rel="preload" as="font" type="font/woff2" crossorigin href="../../SourceCodePro-Semibold.ttf.woff2"><link rel="stylesheet" href="../../normalize.css"><link rel="stylesheet" href="../../rustdoc.css" id="mainThemeStyle"><link rel="stylesheet" href="../../ayu.css" disabled><link rel="stylesheet" href="../../dark.css" disabled><link rel="stylesheet" href="../../light.css" id="themeStyle"><script id="default-settings" ></script><script src="../../storage.js"></script><script defer src="../../source-script.js"></script><script defer src="../../source-files.js"></script><script defer src="../../main.js"></script><noscript><link rel="stylesheet" href="../../noscript.css"></noscript><link rel="alternate icon" type="image/png" href="../../favicon-16x16.png"><link rel="alternate icon" type="image/png" href="../../favicon-32x32.png"><link rel="icon" type="image/svg+xml" href="../../favicon.svg"></head><body class="rustdoc source"><!--[if lte IE 11]><div class="warning">This old browser is unsupported and will most likely display funky things.</div><![endif]--><nav class="sidebar"><a class="sidebar-logo" href="../../anyhow/index.html"><div class="logo-container"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></div></a></nav><main><div class="width-limiter"><nav class="sub"><a class="sub-logo-container" href="../../anyhow/index.html"><img class="rust-logo" src="../../rust-logo.svg" alt="logo"></a><form class="search-form"><div class="search-container"><span></span><input class="search-input" name="search" 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="../../wheel.svg"></a></div></div></form></nav><section id="main-content" class="content"><div class="example-wrap"><pre class="src-line-numbers"><span id="1">1</span> |
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| </pre><pre class="rust"><code><span class="kw">use </span><span class="kw">crate</span>::error::ContextError; |
| <span class="kw">use crate</span>::{Context, Error, StdError}; |
| <span class="kw">use </span>core::convert::Infallible; |
| <span class="kw">use </span>core::fmt::{<span class="self">self</span>, Debug, Display, Write}; |
| |
| <span class="attribute">#[cfg(backtrace)] |
| </span><span class="kw">use </span>std::any::{Demand, Provider}; |
| |
| <span class="kw">mod </span>ext { |
| <span class="kw">use super</span>::<span class="kw-2">*</span>; |
| |
| <span class="kw">pub trait </span>StdError { |
| <span class="kw">fn </span>ext_context<C>(<span class="self">self</span>, context: C) -> Error |
| <span class="kw">where |
| </span>C: Display + Send + Sync + <span class="lifetime">'static</span>; |
| } |
| |
| <span class="attribute">#[cfg(feature = <span class="string">"std"</span>)] |
| </span><span class="kw">impl</span><E> StdError <span class="kw">for </span>E |
| <span class="kw">where |
| </span>E: std::error::Error + Send + Sync + <span class="lifetime">'static</span>, |
| { |
| <span class="kw">fn </span>ext_context<C>(<span class="self">self</span>, context: C) -> Error |
| <span class="kw">where |
| </span>C: Display + Send + Sync + <span class="lifetime">'static</span>, |
| { |
| <span class="kw">let </span>backtrace = <span class="macro">backtrace_if_absent!</span>(<span class="kw-2">&</span><span class="self">self</span>); |
| Error::from_context(context, <span class="self">self</span>, backtrace) |
| } |
| } |
| |
| <span class="kw">impl </span>StdError <span class="kw">for </span>Error { |
| <span class="kw">fn </span>ext_context<C>(<span class="self">self</span>, context: C) -> Error |
| <span class="kw">where |
| </span>C: Display + Send + Sync + <span class="lifetime">'static</span>, |
| { |
| <span class="self">self</span>.context(context) |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><T, E> Context<T, E> <span class="kw">for </span><span class="prelude-ty">Result</span><T, E> |
| <span class="kw">where |
| </span>E: ext::StdError + Send + Sync + <span class="lifetime">'static</span>, |
| { |
| <span class="kw">fn </span>context<C>(<span class="self">self</span>, context: C) -> <span class="prelude-ty">Result</span><T, Error> |
| <span class="kw">where |
| </span>C: Display + Send + Sync + <span class="lifetime">'static</span>, |
| { |
| <span class="comment">// Not using map_err to save 2 useless frames off the captured backtrace |
| // in ext_context. |
| </span><span class="kw">match </span><span class="self">self </span>{ |
| <span class="prelude-val">Ok</span>(ok) => <span class="prelude-val">Ok</span>(ok), |
| <span class="prelude-val">Err</span>(error) => <span class="prelude-val">Err</span>(error.ext_context(context)), |
| } |
| } |
| |
| <span class="kw">fn </span>with_context<C, F>(<span class="self">self</span>, context: F) -> <span class="prelude-ty">Result</span><T, Error> |
| <span class="kw">where |
| </span>C: Display + Send + Sync + <span class="lifetime">'static</span>, |
| F: FnOnce() -> C, |
| { |
| <span class="kw">match </span><span class="self">self </span>{ |
| <span class="prelude-val">Ok</span>(ok) => <span class="prelude-val">Ok</span>(ok), |
| <span class="prelude-val">Err</span>(error) => <span class="prelude-val">Err</span>(error.ext_context(context())), |
| } |
| } |
| } |
| |
| <span class="doccomment">/// ``` |
| /// # type T = (); |
| /// # |
| /// use anyhow::{Context, Result}; |
| /// |
| /// fn maybe_get() -> Option<T> { |
| /// # const IGNORE: &str = stringify! { |
| /// ... |
| /// # }; |
| /// # unimplemented!() |
| /// } |
| /// |
| /// fn demo() -> Result<()> { |
| /// let t = maybe_get().context("there is no T")?; |
| /// # const IGNORE: &str = stringify! { |
| /// ... |
| /// # }; |
| /// # unimplemented!() |
| /// } |
| /// ``` |
| </span><span class="kw">impl</span><T> Context<T, Infallible> <span class="kw">for </span><span class="prelude-ty">Option</span><T> { |
| <span class="kw">fn </span>context<C>(<span class="self">self</span>, context: C) -> <span class="prelude-ty">Result</span><T, Error> |
| <span class="kw">where |
| </span>C: Display + Send + Sync + <span class="lifetime">'static</span>, |
| { |
| <span class="comment">// Not using ok_or_else to save 2 useless frames off the captured |
| // backtrace. |
| </span><span class="kw">match </span><span class="self">self </span>{ |
| <span class="prelude-val">Some</span>(ok) => <span class="prelude-val">Ok</span>(ok), |
| <span class="prelude-val">None </span>=> <span class="prelude-val">Err</span>(Error::from_display(context, <span class="macro">backtrace!</span>())), |
| } |
| } |
| |
| <span class="kw">fn </span>with_context<C, F>(<span class="self">self</span>, context: F) -> <span class="prelude-ty">Result</span><T, Error> |
| <span class="kw">where |
| </span>C: Display + Send + Sync + <span class="lifetime">'static</span>, |
| F: FnOnce() -> C, |
| { |
| <span class="kw">match </span><span class="self">self </span>{ |
| <span class="prelude-val">Some</span>(ok) => <span class="prelude-val">Ok</span>(ok), |
| <span class="prelude-val">None </span>=> <span class="prelude-val">Err</span>(Error::from_display(context(), <span class="macro">backtrace!</span>())), |
| } |
| } |
| } |
| |
| <span class="kw">impl</span><C, E> Debug <span class="kw">for </span>ContextError<C, E> |
| <span class="kw">where |
| </span>C: Display, |
| E: Debug, |
| { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter) -> fmt::Result { |
| f.debug_struct(<span class="string">"Error"</span>) |
| .field(<span class="string">"context"</span>, <span class="kw-2">&</span>Quoted(<span class="kw-2">&</span><span class="self">self</span>.context)) |
| .field(<span class="string">"source"</span>, <span class="kw-2">&</span><span class="self">self</span>.error) |
| .finish() |
| } |
| } |
| |
| <span class="kw">impl</span><C, E> Display <span class="kw">for </span>ContextError<C, E> |
| <span class="kw">where |
| </span>C: Display, |
| { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, f: <span class="kw-2">&mut </span>fmt::Formatter) -> fmt::Result { |
| Display::fmt(<span class="kw-2">&</span><span class="self">self</span>.context, f) |
| } |
| } |
| |
| <span class="kw">impl</span><C, E> StdError <span class="kw">for </span>ContextError<C, E> |
| <span class="kw">where |
| </span>C: Display, |
| E: StdError + <span class="lifetime">'static</span>, |
| { |
| <span class="kw">fn </span>source(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span>(<span class="kw">dyn </span>StdError + <span class="lifetime">'static</span>)> { |
| <span class="prelude-val">Some</span>(<span class="kw-2">&</span><span class="self">self</span>.error) |
| } |
| |
| <span class="attribute">#[cfg(backtrace)] |
| </span><span class="kw">fn </span>provide<<span class="lifetime">'a</span>>(<span class="kw-2">&</span><span class="lifetime">'a </span><span class="self">self</span>, demand: <span class="kw-2">&mut </span>Demand<<span class="lifetime">'a</span>>) { |
| StdError::provide(<span class="kw-2">&</span><span class="self">self</span>.error, demand); |
| } |
| } |
| |
| <span class="kw">impl</span><C> StdError <span class="kw">for </span>ContextError<C, Error> |
| <span class="kw">where |
| </span>C: Display, |
| { |
| <span class="kw">fn </span>source(<span class="kw-2">&</span><span class="self">self</span>) -> <span class="prelude-ty">Option</span><<span class="kw-2">&</span>(<span class="kw">dyn </span>StdError + <span class="lifetime">'static</span>)> { |
| <span class="prelude-val">Some</span>(<span class="kw">unsafe </span>{ <span class="kw">crate</span>::ErrorImpl::error(<span class="self">self</span>.error.inner.by_ref()) }) |
| } |
| |
| <span class="attribute">#[cfg(backtrace)] |
| </span><span class="kw">fn </span>provide<<span class="lifetime">'a</span>>(<span class="kw-2">&</span><span class="lifetime">'a </span><span class="self">self</span>, demand: <span class="kw-2">&mut </span>Demand<<span class="lifetime">'a</span>>) { |
| Provider::provide(<span class="kw-2">&</span><span class="self">self</span>.error, demand); |
| } |
| } |
| |
| <span class="kw">struct </span>Quoted<C>(C); |
| |
| <span class="kw">impl</span><C> Debug <span class="kw">for </span>Quoted<C> |
| <span class="kw">where |
| </span>C: Display, |
| { |
| <span class="kw">fn </span>fmt(<span class="kw-2">&</span><span class="self">self</span>, formatter: <span class="kw-2">&mut </span>fmt::Formatter) -> fmt::Result { |
| formatter.write_char(<span class="string">'"'</span>)<span class="question-mark">?</span>; |
| Quoted(<span class="kw-2">&mut *</span>formatter).write_fmt(<span class="macro">format_args!</span>(<span class="string">"{}"</span>, <span class="self">self</span>.<span class="number">0</span>))<span class="question-mark">?</span>; |
| formatter.write_char(<span class="string">'"'</span>)<span class="question-mark">?</span>; |
| <span class="prelude-val">Ok</span>(()) |
| } |
| } |
| |
| <span class="kw">impl </span>Write <span class="kw">for </span>Quoted<<span class="kw-2">&mut </span>fmt::Formatter<<span class="lifetime">'_</span>>> { |
| <span class="kw">fn </span>write_str(<span class="kw-2">&mut </span><span class="self">self</span>, s: <span class="kw-2">&</span>str) -> fmt::Result { |
| Display::fmt(<span class="kw-2">&</span>s.escape_debug(), <span class="self">self</span>.<span class="number">0</span>) |
| } |
| } |
| |
| <span class="kw">pub</span>(<span class="kw">crate</span>) <span class="kw">mod </span>private { |
| <span class="kw">use super</span>::<span class="kw-2">*</span>; |
| |
| <span class="kw">pub trait </span>Sealed {} |
| |
| <span class="kw">impl</span><T, E> Sealed <span class="kw">for </span><span class="prelude-ty">Result</span><T, E> <span class="kw">where </span>E: ext::StdError {} |
| <span class="kw">impl</span><T> Sealed <span class="kw">for </span><span class="prelude-ty">Option</span><T> {} |
| } |
| </code></pre></div> |
| </section></div></main><div id="rustdoc-vars" data-root-path="../../" data-current-crate="anyhow" data-themes="ayu,dark,light" data-resource-suffix="" data-rustdoc-version="1.66.0-nightly (5c8bff74b 2022-10-21)" ></div></body></html> |
