<!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="API documentation for the Rust `set_hook` fn in crate `std`."> <meta name="keywords" content="rust, rustlang, rust-lang, set_hook"> <title>std::panic::set_hook - Rust</title> <link rel="stylesheet" type="text/css" href="../../normalize.css"> <link rel="stylesheet" type="text/css" href="../../rustdoc.css"> <link rel="stylesheet" type="text/css" href="../../main.css"> <link rel="shortcut icon" href="https://doc.rust-lang.org/favicon.ico"> </head> <body class="rustdoc fn"> <!--[if lte IE 8]> <div class="warning"> This old browser is unsupported and will most likely display funky things. </div> <![endif]--> <nav class="sidebar"> <a href='../../std/index.html'><img src='https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png' alt='logo' width='100'></a> <p class='location'><a href='../index.html'>std</a>::<wbr><a href='index.html'>panic</a></p><script>window.sidebarCurrent = {name: 'set_hook', ty: 'fn', relpath: ''};</script><script defer src="sidebar-items.js"></script> </nav> <nav class="sub"> <form class="search-form js-only"> <div class="search-container"> <input class="search-input" name="search" autocomplete="off" placeholder="Click or press ‘S’ to search, ‘?’ for more options…" type="search"> </div> </form> </nav> <section id='main' class="content"> <h1 class='fqn'><span class='in-band'>Function <a href='../index.html'>std</a>::<wbr><a href='index.html'>panic</a>::<wbr><a class="fn" href=''>set_hook</a></span><span class='out-of-band'><span class='since' title='Stable since Rust version 1.10.0'>1.10.0</span><span id='render-detail'> <a id="toggle-all-docs" href="javascript:void(0)" title="collapse all docs"> [<span class='inner'>−</span>] </a> </span><a class='srclink' href='../../src/std/panicking.rs.html#102-117' title='goto source code'>[src]</a></span></h1> <pre class='rust fn'>pub fn set_hook(hook: <a class="struct" href="../../std/boxed/struct.Box.html" title="struct std::boxed::Box">Box</a><<a class="trait" href="../../std/ops/trait.Fn.html" title="trait std::ops::Fn">Fn</a>(&<a class="struct" href="../../std/panic/struct.PanicInfo.html" title="struct std::panic::PanicInfo">PanicInfo</a>) + <a class="trait" href="../../std/marker/trait.Sync.html" title="trait std::marker::Sync">Sync</a> + <a class="trait" href="../../std/marker/trait.Send.html" title="trait std::marker::Send">Send</a> + 'static>)</pre><div class='docblock'><p>Registers a custom panic hook, replacing any that was previously registered.</p> <p>The panic hook is invoked when a thread panics, but before the panic runtime is invoked. As such, the hook will run with both the aborting and unwinding runtimes. The default hook prints a message to standard error and generates a backtrace if requested, but this behavior can be customized with the <code>set_hook</code> and <code>take_hook</code> functions.</p> <p>The hook is provided with a <code>PanicInfo</code> struct which contains information about the origin of the panic, including the payload passed to <code>panic!</code> and the source code location from which the panic originated.</p> <p>The panic hook is a global resource.</p> <h1 id='panics' class='section-header'><a href='#panics'>Panics</a></h1> <p>Panics if called from a panicking thread.</p> <h1 id='examples' class='section-header'><a href='#examples'>Examples</a></h1> <p>The following will print "Custom panic hook":</p> <pre class="rust rust-example-rendered"> <span class="kw">use</span> <span class="ident">std</span>::<span class="ident">panic</span>; <span class="ident">panic</span>::<span class="ident">set_hook</span>(<span class="ident">Box</span>::<span class="ident">new</span>(<span class="op">|</span>_<span class="op">|</span> { <span class="macro">println</span><span class="macro">!</span>(<span class="string">"Custom panic hook"</span>); })); <span class="macro">panic</span><span class="macro">!</span>(<span class="string">"Normal panic"</span>);<a class="test-arrow" target="_blank" href="https://play.rust-lang.org/?code=fn%20main()%20%7B%0Ause%20std%3A%3Apanic%3B%0A%0Apanic%3A%3Aset_hook(Box%3A%3Anew(%7C_%7C%20%7B%0A%20%20%20%20println!(%22Custom%20panic%20hook%22)%3B%0A%7D))%3B%0A%0Apanic!(%22Normal%20panic%22)%3B%0A%7D">Run</a></pre> </div></section> <section id='search' class="content hidden"></section> <section class="footer"></section> <aside id="help" class="hidden"> <div> <h1 class="hidden">Help</h1> <div class="shortcuts"> <h2>Keyboard Shortcuts</h2> <dl> <dt>?</dt> <dd>Show this help dialog</dd> <dt>S</dt> <dd>Focus the search field</dd> <dt>⇤</dt> <dd>Move up in search results</dd> <dt>⇥</dt> <dd>Move down in search results</dd> <dt>⏎</dt> <dd>Go to active search result</dd> <dt>+</dt> <dd>Collapse/expand all sections</dd> </dl> </div> <div class="infos"> <h2>Search Tricks</h2> <p> Prefix searches with a type followed by a colon (e.g. <code>fn:</code>) to restrict the search to a given type. </p> <p> Accepted types are: <code>fn</code>, <code>mod</code>, <code>struct</code>, <code>enum</code>, <code>trait</code>, <code>type</code>, <code>macro</code>, and <code>const</code>. </p> <p> Search functions by type signature (e.g. <code>vec -> usize</code> or <code>* -> vec</code>) </p> </div> </div> </aside> <script> window.rootPath = "../../"; window.currentCrate = "std"; </script> <script src="../../main.js"></script> <script defer src="../../search-index.js"></script> </body> </html>