<!--
  Copyright 2019 The Go Authors. All rights reserved.
  Use of this source code is governed by a BSD-style
  license that can be found in the LICENSE file.
-->

<!DOCTYPE html>
<html lang="en">
<!-- This will capture unhandled errors during page load for reporting later. -->
<script>window.addEventListener('error', window.__err=function f(e){f.p=f.p||[];f.p.push(e)});</script>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
{{if .MetaDescription.String}}
  {{.MetaDescription}}
{{else}}
  <meta name="Description" content="Go is an open source programming language that makes it easy to build simple, reliable, and efficient software.">
{{end}}
<meta class="js-gtmID" data-gtmid="{{.GoogleTagManagerID}}">
<link href="/static/css/stylesheet.css?version={{.AppVersionLabel}}" rel="stylesheet">
<link href="/third_party/dialog-polyfill/dialog-polyfill.css?version={{.AppVersionLabel}}" rel="stylesheet">
<title>{{if .HTMLTitle}}{{.HTMLTitle}} · {{end}}pkg.go.dev</title>
{{block "pre_content" .}}{{end}}
<body class="Site{{if .AllowWideContent}} Site--wide{{end}}{{if (.Experiments.IsActive "unit-page")}} Site--redesign{{end}}">
<header class="Site-header Site-header--dark">
  <div class="Banner">
    <div class="Banner-inner">
      <div class="Banner-message">Black Lives Matter</div>
      <a class="Banner-action"
         href="https://support.eji.org/give/153413/#!/donation/checkout"
         target="_blank"
         rel="noopener">Support the Equal Justice Initiative</a>
    </div>
  </div>
  <div class="Header">
    <nav class="Header-nav">
      <a href="https://go.dev/" class="Header-logoLink">
        <img class="Header-logo" src="/static/img/go-logo-white.svg" alt="Go">
      </a>
      {{template "header_search" .}}
      <ul class="Header-menu">
        <li class="Header-menuItem">
          <a href="https://go.dev/solutions" title="Why Go">Why Go</a>
        </li>
        <li class="Header-menuItem">
          <a href="https://learn.go.dev" title="Getting Started">Getting Started</a>
        </li>
        <li class="Header-menuItem Header-menuItem--active">
          <a href="/" title="Discover Packages">Discover Packages</a>
        </li>
        <li class="Header-menuItem">
          <a href="https://go.dev/about" title="">About</a>
        </li>
      </ul>
      <button class="Header-navOpen js-headerMenuButton" aria-label="Open navigation.">
      </button>
    </nav>
  </div>
</header>
<aside class="NavigationDrawer js-header">
  <nav class="NavigationDrawer-nav">
    <div class="NavigationDrawer-header">
      <a href="https://go.dev/">
        <img class="NavigationDrawer-logo" src="/static/img/go-logo-blue.svg" alt="Go.">
      </a>
      <button class="NavigationDrawer-close js-headerMenuButton" aria-label="Close navigation.">
      </button>
    </div>
    <ul class="NavigationDrawer-list">
      <li class="NavigationDrawer-listItem">
        <a href="https://go.dev/solutions" title="Why Go">Why Go</a>
      </li>
      <li class="NavigationDrawer-listItem">
        <a href="https://learn.go.dev" title="Getting Started">Getting Started</a>
      </li>
      <li class="NavigationDrawer-listItem NavigationDrawer-listItem--active">
        <a href="/" title="Discover Packages">Discover Packages</a>
      </li>
      <li class="NavigationDrawer-listItem">
        <a href="https://go.dev/about" title="">About</a>
      </li>
      <li class="NavigationDrawer-listItem">
        <a href="https://golang.org" title="golang.org">golang.org</a>
      </li>
    </ul>
  </nav>
</aside>
<div class="NavigationDrawer-scrim js-scrim" role="presentation">
</div>
{{if (.Experiments.IsActive "unit-page")}}
  <div class="Site-content">{{block "main_content" .}}{{end}}</div>
{{else}}
  <main class="Site-content">{{block "main_content" .}}{{end}}</main>
{{end}}
<footer class="Site-footer">
  {{block "pre_footer" .}}{{end}}
  <div class="Footer">
    <div class="Footer-links">
      <div class="Footer-linkColumn">
        <a href="https://go.dev/solutions" class="Footer-link Footer-link--primary" title="Why Go">
          Why Go
        </a>
        <a href="https://go.dev/solutions#use-cases" class="Footer-link" title="Use Cases">
          Use Cases
        </a>
        <a href="https://go.dev/solutions#case-studies" class="Footer-link" title="Case Studies">
          Case Studies
        </a>
      </div>
      <div class="Footer-linkColumn">
        <a href="https://learn.go.dev/" class="Footer-link Footer-link--primary" title="Getting Started">
          Getting Started
        </a>
        <a href="https://play.golang.org" class="Footer-link" title="">
          Playground
        </a>
        <a href="https://tour.golang.org" class="Footer-link" title="">
          Tour
        </a>
        <a href="https://stackoverflow.com/questions/tagged/go?tab=Newest" class="Footer-link" title="">
          Stack Overflow
        </a>
      </div>
      <div class="Footer-linkColumn">
        <a href="https://pkg.go.dev" class="Footer-link Footer-link--primary" title="Discover Packages">
          Discover Packages
        </a>
      </div>
      <div class="Footer-linkColumn">
        <a href="https://go.dev/about" class="Footer-link Footer-link--primary" title="About">
          About
        </a>
        <a href="https://golang.org/dl/" class="Footer-link" title="">
          Download
        </a>
        <a href="https://blog.golang.org" class="Footer-link" title="">
          Blog
        </a>
        <a href="https://golang.org/doc/devel/release.html" class="Footer-link" title="">
          Release Notes
        </a>
        <a href="https://blog.golang.org/go-brand" class="Footer-link" title="">
          Brand Guidelines
        </a>
        <a href="https://golang.org/conduct" class="Footer-link">
          Code of Conduct
        </a>
      </div>
      <div class="Footer-linkColumn">
        <a href="https://www.twitter.com/golang" class="Footer-link Footer-link--primary" title="Connect">
          Connect
        </a>
        <a href="https://www.twitter.com/golang" class="Footer-link" title="">
          Twitter
        </a>
        <a href="https://github.com/golang" class="Footer-link" title="">
          GitHub
        </a>
        <a href="https://invite.slack.golangbridge.org/" class="Footer-link" title="">
          Slack
        </a>
        <a href="https://www.meetup.com/pro/go" class="Footer-link" title="">
          Meetup
        </a>
      </div>
    </div>
  </div>
  <div class="Footer">
    <div class="Container Container--fullBleed">
      <div class="Footer-bottom">
        <img class="Footer-gopher" loading="lazy" src="/static/img/pilot-bust.svg" alt="The Go Gopher">
        <ul class="Footer-listRow">
          <li class="Footer-listItem"><a href="https://go.dev/copyright">Copyright</a></li>
          <li class="Footer-listItem"><a href="https://go.dev/tos">Terms of Service</a></li>
          <li class="Footer-listItem"><a href="http://www.google.com/intl/en/policies/privacy/" target="_blank" rel="noopener">Privacy
              Policy</a></li>
          <li class="Footer-listItem">
            <a href="https://golang.org/s/pkgsite-feedback" target="_blank" rel="noopener">
              Report an Issue
            </a>
          </li>
          <li class="Footer-listItem"><a href="https://golang.org" target="_blank" rel="noopener">golang.org</a></li>
        </ul>
        <a class="Footer-googleLogo" href="https://google.com" target="_blank" rel="noopener">
          <img class="Footer-googleLogoImg" loading="lazy" src="/static/img/google-white.png" alt="Google logo">
        </a>
      </div>
    </div>
  </div>
</footer>

<script>
  function loadScript(src, props = {}) {
    let s = document.createElement('script');
    s.src = src;
    for (const [k, v] of Object.entries(props)) {
      s[k] = v
    }
    document.head.appendChild(s);
  }
  loadScript('/static/js/web-vitals.js', {type: 'module', defer: true});
  loadScript("/static/js/base.min.js");
</script>

{{block "post_content" .}}{{end}}

{{if .GoogleTagManagerID}}
<script async>
  const gtmId = document.querySelector('.js-gtmID').dataset.gtmid; // this will throw if the querySelector can’t find the element
  if (!gtmId) {
    throw new Error('Google Tag Manager ID not found');
  }
  loadScript(`https://www.googletagmanager.com/gtm.js?id=${gtmId}`);
</script>
<noscript>
  <iframe src="https://www.googletagmanager.com/ns.html?id={{.GoogleTagManagerID}}"
          height="0" width="0" style="display:none;visibility:hidden">
  </iframe>
</noscript>
{{end}}

{{if (.Experiments.IsActive "autocomplete")}}
<script>
  loadScript("/third_party/autoComplete.js/autoComplete.min.js");
  loadScript("/static/js/completion.min.js");
</script>
{{end}}