1<html> 2<head> 3<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII"> 4<title>Macro BOOST_CONTRACT_PUBLIC_FUNCTION</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. Boost.Contract 1.0.0"> 8<link rel="up" href="reference.html#header.boost.contract_macro_hpp" title="Header <boost/contract_macro.hpp>"> 9<link rel="prev" href="BOOST_CO_idm45394998534992.html" title="Macro BOOST_CONTRACT_STATIC_PUBLIC_FUNCTION"> 10<link rel="next" href="BOOST_CO_idm45394998486064.html" title="Macro BOOST_CONTRACT_PUBLIC_FUNCTION_OVERRIDE"> 11</head> 12<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF"> 13<table cellpadding="2" width="100%"><tr> 14<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../boost.png"></td> 15<td align="center"><a 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class="refnamediv"> 28<h2><span class="refentrytitle">Macro BOOST_CONTRACT_PUBLIC_FUNCTION</span></h2> 29<p>BOOST_CONTRACT_PUBLIC_FUNCTION — Program contracts that can be completely disabled at compile-time for non-static public functions that do not override. </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_PUBLIC_FUNCTION(...)</pre></div> 35<div class="refsect1"> 36<a name="idm45707992128928"></a><h2>Description</h2> 37<p>This is used together with <code class="computeroutput"><a class="link" href="BOOST_CO_idm45394998748208.html" title="Macro BOOST_CONTRACT_PRECONDITION">BOOST_CONTRACT_PRECONDITION</a></code>, <code class="computeroutput"><a class="link" href="BOOST_CO_idm45394998736528.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 preconditions, postconditions, exception guarantees, and old value copies at body that can be completely disabled at compile-time for non-static public functions (virtual or not, void or not) that do not override:</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="comment">// Non-virtual (same if void).</span> 48 <span class="identifier">t</span> <span class="identifier">f</span><span class="special">(</span><span class="special">...</span><span class="special">)</span> <span class="special">{</span> 49 <span class="identifier">t</span> <span class="identifier">result</span><span class="special">;</span> 50 <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> 51 <span class="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</span><span class="special">(</span><span class="keyword">this</span><span class="special">)</span> 52 <span class="identifier">BOOST_CONTRACT_PRECONDITION</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> 53 <span class="identifier">BOOST_CONTRACT_ASSERT</span><span class="special">(</span><span class="special">...</span><span class="special">)</span><span class="special">;</span> 54 <span class="special">...</span> 55 <span class="special">}</span><span class="special">)</span> 56 <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> 57 <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_expr</span><span class="special">)</span><span class="special">;</span> 58 <span class="special">...</span> 59 <span class="special">}</span><span class="special">)</span> 60 <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> 61 <span class="identifier">BOOST_CONTRACT_ASSERT</span><span class="special">(</span><span class="special">...</span><span class="special">)</span><span class="special">;</span> 62 <span class="special">...</span> 63 <span class="special">}</span><span class="special">)</span> 64 <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> 65 <span class="identifier">BOOST_CONTRACT_ASSERT</span><span class="special">(</span><span class="special">...</span><span class="special">)</span><span class="special">;</span> 66 <span class="special">...</span> 67 <span class="special">}</span><span class="special">)</span> 68 <span class="special">;</span> <span class="comment">// Trailing `;` is required.</span> 69 70 <span class="special">...</span> <span class="comment">// Function body (use `return result = return_expr`).</span> 71 <span class="special">}</span> 72 73 <span class="comment">// Virtual and void.</span> 74 <span class="keyword">virtual</span> <span class="keyword">void</span> <span class="identifier">g</span><span class="special">(</span><span class="special">...</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">contract</span><span class="special">::</span><span class="identifier">virtual_</span><span class="special">*</span> <span class="identifier">v</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="special">{</span> 75 <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> 76 <span class="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</span><span class="special">(</span><span class="identifier">v</span><span class="special">,</span> <span class="keyword">this</span><span class="special">)</span> 77 <span class="special">...</span> 78 <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> 79 <span class="identifier">old_var</span> <span class="special">=</span> <span class="identifier">BOOST_CONTRACT_OLDOF</span><span class="special">(</span><span class="identifier">v</span><span class="special">,</span> <span class="identifier">old_expr</span><span class="special">)</span><span class="special">;</span> 80 <span class="special">...</span> 81 <span class="special">}</span><span class="special">)</span> 82 <span class="special">...</span> 83 <span class="special">;</span> <span class="comment">// Trailing `;` is required.</span> 84 85 <span class="special">...</span> <span class="comment">// Function body.</span> 86 <span class="special">}</span> 87 88 <span class="comment">// Virtual and non-void.</span> 89 <span class="keyword">virtual</span> <span class="identifier">t</span> <span class="identifier">h</span><span class="special">(</span><span class="special">...</span><span class="special">,</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">contract</span><span class="special">::</span><span class="identifier">virtual_</span><span class="special">*</span> <span class="identifier">v</span> <span class="special">=</span> <span class="number">0</span><span class="special">)</span> <span class="special">{</span> 90 <span class="identifier">t</span> <span class="identifier">result</span><span class="special">;</span> 91 <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> 92 <span class="identifier">BOOST_CONTRACT_PUBLIC_FUNCTION</span><span class="special">(</span><span class="identifier">v</span><span class="special">,</span> <span class="identifier">result</span><span class="special">,</span> <span class="keyword">this</span><span class="special">)</span> 93 <span class="special">...</span> 94 <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> 95 <span class="identifier">old_var</span> <span class="special">=</span> <span class="identifier">BOOST_CONTRACT_OLDOF</span><span class="special">(</span><span class="identifier">v</span><span class="special">,</span> <span class="identifier">old_expr</span><span class="special">)</span><span class="special">;</span> 96 <span class="special">...</span> 97 <span class="special">}</span><span class="special">)</span> 98 <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="identifier">t</span> <span class="keyword">const</span><span class="special">&</span> <span class="identifier">result</span><span class="special">)</span> <span class="special">{</span> <span class="comment">// Optional</span> 99 <span class="identifier">BOOST_CONTRACT_ASSERT</span><span class="special">(</span><span class="special">...</span><span class="special">)</span><span class="special">;</span> 100 <span class="special">...</span> 101 <span class="special">}</span><span class="special">)</span> 102 <span class="special">...</span> 103 <span class="special">;</span> <span class="comment">// Trailing `;` is required.</span> 104 105 <span class="special">...</span> <span class="comment">// Function body (use `return result = return_expr`).</span> 106 <span class="special">}</span> 107 108 <span class="special">...</span> 109<span class="special">}</span><span class="special">;</span> 110</pre> 111<p>For optimization, this can be omitted for non-virtual public functions that do not have preconditions, postconditions and exception guarantees, within classes that have no invariants. Virtual public functions should always use <code class="computeroutput"><a class="link" href="BOOST_CO_idm45394998517984.html" title="Macro BOOST_CONTRACT_PUBLIC_FUNCTION">BOOST_CONTRACT_PUBLIC_FUNCTION</a></code> otherwise this library will not be able to correctly use them for subcontracting.</p> 112<p>This is an overloaded variadic macro and it can be used in the following different ways (note that no code is generated when <code class="computeroutput"><a class="link" href="BOOST_CO_idm45394999586272.html" title="Macro BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</a></code> is defined).</p> 113<p>1. <code class="computeroutput">BOOST_CONTRACT_PUBLIC_FUNCTION(obj)</code> expands to code equivalent to the following (for non-virtual public functions that are not static and do not override, returning void or not):</p> 114<pre class="programlisting"><span class="preprocessor">#ifndef</span> <span class="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</span> 115 <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> 116 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">contract</span><span class="special">::</span><span class="identifier">public_function</span><span class="special">(</span><span class="identifier">obj</span><span class="special">)</span> 117<span class="preprocessor">#endif</span> 118</pre> 119<p>2. <code class="computeroutput">BOOST_CONTRACT_PUBLIC_FUNCTION(v, obj)</code> expands to code equivalent to the following (for virtual public functions that do not override, returning void):</p> 120<pre class="programlisting"><span class="preprocessor">#ifndef</span> <span class="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</span> 121 <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> 122 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">contract</span><span class="special">::</span><span class="identifier">public_function</span><span class="special">(</span><span class="identifier">v</span><span class="special">,</span> <span class="identifier">obj</span><span class="special">)</span> 123<span class="preprocessor">#endif</span> 124</pre> 125<p>3. <code class="computeroutput">BOOST_CONTRACT_PUBLIC_FUNCTION(v, r, obj)</code> expands to code equivalent to the following (for virtual public functions that do not override, not returning void):</p> 126<pre class="programlisting"><span class="preprocessor">#ifndef</span> <span class="identifier">BOOST_CONTRACT_NO_PUBLIC_FUNCTIONS</span> 127 <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> 128 <span class="identifier">boost</span><span class="special">::</span><span class="identifier">contract</span><span class="special">::</span><span class="identifier">public_function</span><span class="special">(</span><span class="identifier">v</span><span class="special">,</span> <span class="identifier">r</span><span class="special">,</span> <span class="identifier">obj</span><span class="special">)</span> 129<span class="preprocessor">#endif</span> 130</pre> 131<p>Where (these are all variadic macro parameters so they can contain commas not protected by round parenthesis):</p> 132<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; "> 133<li class="listitem"><p><code class="computeroutput"><span class="bold"><strong>v</strong></span></code> is the extra parameter of type <code class="computeroutput"><a class="link" href="boost/contract/virtual_.html" title="Class virtual_">boost::contract::virtual_</a></code><code class="computeroutput">*</code> and default value <code class="computeroutput">0</code> from the enclosing virtual public function declaring the contract. </p></li> 134<li class="listitem"><p><code class="computeroutput"><span class="bold"><strong>r</strong></span></code> is a reference to the return value of the enclosing virtual public function declaring the contract. This is usually a local variable declared by the enclosing virtual public function just before the contract, but programmers must set it to the actual value being returned by the function at each <code class="computeroutput">return</code> statement. </p></li> 135<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 public function declaring the contract. This object might be mutable, <code class="computeroutput">const</code>, <code class="computeroutput">volatile</code>, or <code class="computeroutput">const volatile</code> depending on the cv-qualifier of the enclosing function (volatile public functions will check volatile class invariants, see <a class="link" href="boost_contract/extras.html#boost_contract.extras.volatile_public_functions" title="Volatile Public Functions"> 136 Volatile Public Functions</a>). </p></li> 137<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> 138</ul></div> 139<p> 140</p> 141<p><span class="bold"><strong>See Also:</strong></span></p> 142<p> <a class="link" href="boost_contract/extras.html#boost_contract.extras.disable_contract_compilation__macro_interface_" title="Disable Contract Compilation (Macro Interface)"> 143 Disable Contract Compilation</a>, <a class="link" href="boost_contract/tutorial.html#boost_contract.tutorial.public_functions" title="Public Functions"> Public Functions</a>, <a class="link" href="boost_contract/tutorial.html#boost_contract.tutorial.virtual_public_functions" title="Virtual Public Functions"> 144 Virtual Public Functions</a> </p> 145<p> 146</p> 147<p> 148</p> 149</div> 150</div> 151<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr> 152<td align="left"></td> 153<td align="right"><div class="copyright-footer">Copyright © 2008-2019 Lorenzo Caminiti<p> 154 Distributed under the Boost Software License, Version 1.0 (see accompanying 155 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>) 156 </p> 157</div></td> 158</tr></table> 159<hr> 160<div class="spirit-nav"> 161<a accesskey="p" href="BOOST_CO_idm45394998534992.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_idm45394998486064.html"><img src="../../../../doc/src/images/next.png" alt="Next"></a> 162</div> 163</body> 164</html> 165