1<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> 2<html><meta http-equiv="Content-Type" content="text/html; charset=utf-8"> 3<title>basic_result<T> - Boost.Outcome documentation</title> 4<link rel="stylesheet" href="../../css/boost.css" type="text/css"> 5<meta name="generator" content="Hugo 0.52 with Boostdoc theme"> 6<meta name="viewport" content="width=device-width,initial-scale=1.0"/> 7 8<link rel="icon" href="../../images/favicon.ico" type="image/ico"/> 9<body><div class="spirit-nav"> 10<a accesskey="p" href="../../reference/concepts/basic_outcome.html"><img src="../../images/prev.png" alt="Prev"></a> 11 <a accesskey="u" href="../../reference/concepts.html"><img src="../../images/up.png" alt="Up"></a> 12 <a accesskey="h" href="../../index.html"><img src="../../images/home.png" alt="Home"></a><a accesskey="n" href="../../reference/concepts/value_or_error.html"><img src="../../images/next.png" alt="Next"></a></div><div id="content"> 13 <div class="titlepage"><div><div><h1 style="clear: both"><code>basic_result<T></code></h1></div></div></div> 14 <p>If on C++ 20 or the Concepts TS is enabled, a boolean concept matching types which have <code>value_type</code>, <code>error_type</code> and <code>no_value_policy_type</code> member typedefs; that the type is convertible to <code>basic_result<value_type, error_type, no_value_policy_type></code>; that <code>basic_result<value_type, error_type, no_value_policy_type></code> is a base of the type.</p> 15 16<p>If without Concepts, a static constexpr bool which is true for types matching the same requirements, using a SFINAE based emulation.</p> 17 18<p>This concept matches any type which provides the same typedefs as a <a href="../../reference/types/basic_result.html" class="api-reference"><code>basic_result<T, E, NoValuePolicy></code></a> 19, has that <code>basic_result</code> as a base class, and is implicitly convertible to <code>basic_result</code>. Whilst not guaranteed, it is very likely that the type is a <code>basic_result</code>, or inherits publicly from a <code>basic_result</code>. If you want something which matches any value-or-error type, consider <a href="../../reference/concepts/value_or_error.html" class="api-reference"><code>value_or_error<T></code></a> 20. If you want something which exactly matches <code>basic_result</code>, use <a href="../../reference/traits/is_basic_result.html" class="api-reference"><code>is_basic_result<T></code></a> 21.</p> 22 23<p><em>Namespace</em>: <code>BOOST_OUTCOME_V2_NAMESPACE::concepts</code></p> 24 25<p><em>Header</em>: <code><boost/outcome/basic_result.hpp></code></p> 26 27 28 </div><p><small>Last revised: May 24, 2020 at 12:48:39 +0100</small></p> 29<hr> 30<div class="spirit-nav"> 31<a accesskey="p" href="../../reference/concepts/basic_outcome.html"><img src="../../images/prev.png" alt="Prev"></a> 32 <a accesskey="u" href="../../reference/concepts.html"><img src="../../images/up.png" alt="Up"></a> 33 <a accesskey="h" href="../../index.html"><img src="../../images/home.png" alt="Home"></a><a accesskey="n" href="../../reference/concepts/value_or_error.html"><img src="../../images/next.png" alt="Next"></a></div></body> 34</html> 35
