1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=UTF-8"> 4<title>Macro BOOST_CONTRACT_CONSTRUCTOR</title> 5<link rel="stylesheet" href="../../../../doc/src/boostbook.css" type="text/css"> 6<meta name="generator" content="DocBook XSL Stylesheets V1.79.1"> 7<link rel="home" href="index.html" title="Chapter 1. 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20</tr></table> 21<hr> 22<div class="spirit-nav"> 23<a accesskey="p" href="BOOST_CO_idm46268584433936.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="reference.html#header.boost.contract_macro_hpp"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="BOOST_CO_idm46268584400144.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 24</div> 25<div class="refentry"> 26<a name="BOOST_CONTRACT_CONSTRUCTOR"></a><div class="titlepage"></div> 27<div class="refnamediv"> 28<h2><span class="refentrytitle">Macro BOOST_CONTRACT_CONSTRUCTOR</span></h2> 29<p>BOOST_CONTRACT_CONSTRUCTOR — Program contracts that can be completely disabled at compile-time for constructors. </p> 30</div> 31<h2 xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv-title">Synopsis</h2> 32<div xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" class="refsynopsisdiv"><pre class="synopsis"><span class="comment">// In header: <<a class="link" href="reference.html#header.boost.contract_macro_hpp" title="Header <boost/contract_macro.hpp>">boost/contract_macro.hpp</a>> 33 34</span>BOOST_CONTRACT_CONSTRUCTOR(...)</pre></div> 35<div class="refsect1"> 36<a name="idm45988675378992"></a><h2>Description</h2> 37<p>This is used together with <code class="computeroutput"><a class="link" href="BOOST_CO_idm46268584548992.html" title="Macro BOOST_CONTRACT_POSTCONDITION">BOOST_CONTRACT_POSTCONDITION</a></code>, <code class="computeroutput"><a class="link" href="BOOST_CONTRACT_EXCEPT.html" title="Macro BOOST_CONTRACT_EXCEPT">BOOST_CONTRACT_EXCEPT</a></code>, and <code class="computeroutput"><a class="link" href="BOOST_CONTRACT_OLD.html" title="Macro BOOST_CONTRACT_OLD">BOOST_CONTRACT_OLD</a></code> to specify postconditions, exception guarantees, and old value copies at body that can be completely disabled at compile-time for constructors (see <code class="computeroutput"><a class="link" href="BOOST_CO_idm46268584400144.html" title="Macro BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION">BOOST_CONTRACT_CONSTRUCTOR_PRECONDITION</a></code> to specify preconditions for constructors):</p> 38<pre class="programlisting"><span class="keyword">class</span> <span class="identifier">u</span> <span class="special">{</span> 39 <span class="keyword">friend</span> <span class="keyword">class</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">contract</span><span class="special">::</span><span class="identifier">access</span><span class="special">;</span> 40 41 <span class="identifier">BOOST_CONTRACT_INVARIANT</span><span class="special">(</span><span class="special">{</span> <span class="comment">// Optional (as for static and volatile).</span> 42 <span class="identifier">BOOST_CONTRACT_ASSERT</span><span class="special">(</span><span class="special">...</span><span class="special">)</span><span class="special">;</span> 43 <span class="special">...</span> 44 <span class="special">}</span><span class="special">)</span> 45 46<span class="keyword">public</span><span class="special">:</span> 47 <span class="identifier">u</span><span class="special">(</span><span class="special">...</span><span class="special">)</span> <span class="special">{</span> 48 <span class="identifier">BOOST_CONTRACT_OLD_PTR</span><span class="special">(</span><span class="identifier">old_type</span><span class="special">)</span><span class="special">(</span><span class="identifier">old_var</span><span class="special">)</span><span class="special">;</span> 49 <span class="identifier">BOOST_CONTRACT_CONSTRUCTOR</span><span class="special">(</span><span class="keyword">this</span><span class="special">)</span> 50 <span class="comment">// No `PRECONDITION` (use `CONSTRUCTOR_PRECONDITION` if needed).</span> 51 <span class="identifier">BOOST_CONTRACT_OLD</span><span class="special">(</span><span class="special">[</span><span class="special">&</span><span class="special">]</span> <span class="special">{</span> <span class="comment">// Optional.</span> 52 <span class="identifier">old_var</span> <span class="special">=</span> <span class="identifier">BOOST_CONTRACT_OLDOF</span><span class="special">(</span><span class="identifier">old_epxr</span><span class="special">)</span><span class="special">;</span> 53 <span class="special">...</span> 54 <span class="special">}</span><span class="special">)</span> 55 <span class="identifier">BOOST_CONTRACT_POSTCONDITION</span><span class="special">(</span><span class="special">[</span><span class="special">&</span><span class="special">]</span> <span class="special">{</span> <span class="comment">// Optional.</span> 56 <span class="identifier">BOOST_CONTRACT_ASSERT</span><span class="special">(</span><span class="special">...</span><span class="special">)</span><span class="special">;</span> 57 <span class="special">...</span> 58 <span class="special">}</span><span class="special">)</span> 59 <span class="identifier">BOOST_CONTRACT_EXCEPT</span><span class="special">(</span><span class="special">[</span><span class="special">&</span><span class="special">]</span> <span class="special">{</span> <span class="comment">// Optional.</span> 60 <span class="identifier">BOOST_CONTRACT_ASSERT</span><span class="special">(</span><span class="special">...</span><span class="special">)</span><span class="special">;</span> 61 <span class="special">...</span> 62 <span class="special">}</span><span class="special">)</span> 63 <span class="special">;</span> <span class="comment">// Trailing `;` is required.</span> 64 65 <span class="special">...</span> <span class="comment">// Constructor body.</span> 66 <span class="special">}</span> 67 68 <span class="special">...</span> 69<span class="special">}</span><span class="special">;</span> 70</pre> 71<p>For optimization, this can be omitted for constructors that do not have postconditions and exception guarantees, within classes that have no invariants.</p> 72<p><code class="computeroutput">BOOST_CONTRACT_CONSTRUCTOR(obj)</code> expands to code equivalent to the following (note that no code is generated when <code class="computeroutput"><a class="link" href="BOOST_CO_idm46268585417872.html" title="Macro BOOST_CONTRACT_NO_CONSTRUCTORS">BOOST_CONTRACT_NO_CONSTRUCTORS</a></code> is defined):</p> 73<pre class="programlisting"><span class="preprocessor">#ifndef</span> <span class="identifier">BOOST_CONTRACT_NO_CONSTRUCTORS</span> 74 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">contract</span><span class="special">::</span><span class="identifier">check</span> <span class="identifier">internal_var</span> <span class="special">=</span> 75 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">contract</span><span class="special">::</span><span class="identifier">constructor</span><span class="special">(</span><span class="identifier">obj</span><span class="special">)</span> 76<span class="preprocessor">#endif</span> 77</pre> 78<p>Where:</p> 79<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 80<li class="listitem"><p><code class="computeroutput"><span class="bold"><strong>obj</strong></span></code> is the object <code class="computeroutput">this</code> from the scope of the enclosing constructor declaring the contract. Constructors check all class invariants, including static and volatile invariants (see <code class="computeroutput"><a class="link" href="BOOST_CONTRACT_INVARIANT.html" title="Macro BOOST_CONTRACT_INVARIANT">BOOST_CONTRACT_INVARIANT</a></code>, <code class="computeroutput"><a class="link" href="BOOST_CO_idm46268584433936.html" title="Macro BOOST_CONTRACT_STATIC_INVARIANT">BOOST_CONTRACT_STATIC_INVARIANT</a></code>, and <code class="computeroutput"><a class="link" href="BOOST_CO_idm46268584447792.html" title="Macro BOOST_CONTRACT_INVARIANT_VOLATILE">BOOST_CONTRACT_INVARIANT_VOLATILE</a></code>). (This is a variadic macro parameter so it can contain commas not protected by round parenthesis.) </p></li> 81<li class="listitem"><p><code class="computeroutput"><span class="bold"><strong>internal_var</strong></span></code> is a variable name internally generated by this library (this name is unique but only on different line numbers so this macro cannot be expanded multiple times on the same line).</p></li> 82</ul></div> 83<p> 84</p> 85<p><span class="bold"><strong>See Also:</strong></span></p> 86<p> <a class="link" href="boost_contract/extras.html#boost_contract.extras.disable_contract_compilation__macro_interface_" title="Disable Contract Compilation (Macro Interface)"> 87 Disable Contract Compilation</a>, <a class="link" href="boost_contract/tutorial.html#boost_contract.tutorial.constructors" title="Constructors"> Constructors</a> </p> 88<p> 89</p> 90<p> 91</p> 92</div> 93</div> 94<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 95<td align="left"></td> 96<td align="right"><div class="copyright-footer">Copyright © 2008-2019 Lorenzo Caminiti<p> 97 Distributed under the Boost Software License, Version 1.0 (see accompanying 98 file LICENSE_1_0.txt or a copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>) 99 </p> 100</div></td> 101</tr></table> 102<hr> 103<div class="spirit-nav"> 104<a accesskey="p" href="BOOST_CO_idm46268584433936.html"><img src="../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="reference.html#header.boost.contract_macro_hpp"><img src="../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="index.html"><img src="../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="BOOST_CO_idm46268584400144.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 105</div> 106</body> 107</html> 108
