boost-react-native-bundle

<?xml version="1.0" encoding="utf-8"?>  <!DOCTYPE library PUBLIC "-//Boost//DTD BoostBook XML V1.0//EN" "http://www.boost.org/tools/boostbook/dtd/boostbook.dtd"> <library-reference id="function.reference" last-revision="$Date$"> <section id="function.definitions"> <title>Definitions</title> <para> <itemizedlist> <listitem> <para>A function object <computeroutput>f</computeroutput> is <emphasis>compatible</emphasis> if for the given set of argument types <computeroutput>Arg1</computeroutput>, <computeroutput>Arg2</computeroutput>, ..., <computeroutput>ArgN</computeroutput> and a return type <computeroutput>ResultType</computeroutput>, the appropriate following function is well-formed: <programlisting> <emphasis>// if ResultType is not <emphasis role="bold">void</emphasis></emphasis> ResultType foo(Arg1 arg1, Arg2 arg2, ..., Arg<emphasis>N</emphasis> arg<emphasis>N</emphasis>) { <emphasis role="bold">return</emphasis> f(arg1, arg2, ..., arg<emphasis>N</emphasis>); } <emphasis>// if ResultType is <emphasis role="bold">void</emphasis></emphasis> ResultType foo(Arg1 arg1, Arg2 arg2, ..., Arg<emphasis>N</emphasis> arg<emphasis>N</emphasis>) { f(arg1, arg2, ..., arg<emphasis>N</emphasis>); } </programlisting></para> <para> A special provision is made for pointers to member functions. Though they are not function objects, Boost.Function will adapt them internally to function objects. This requires that a pointer to member function of the form <code>R (X::*mf)(Arg1, Arg2, ..., ArgN) cv-quals</code> be adapted to a function object with the following function call operator overloads: <programlisting> <emphasis role="bold">template</emphasis><<emphasis role="bold">typename P</emphasis>> R <emphasis role="bold">operator</emphasis>()(<emphasis>cv-quals</emphasis> P& x, Arg1 arg1, Arg2 arg2, ..., Arg<emphasis>N</emphasis> arg<emphasis>N</emphasis>) <emphasis role="bold">const</emphasis> { <emphasis role="bold">return</emphasis> (*x).*mf(arg1, arg2, ..., arg<emphasis>N</emphasis>); } </programlisting> </para> </listitem> <listitem> <para>A function object <code>f</code> of type <code>F</code> is <emphasis>stateless</emphasis> if it is a function pointer or if <code><classname>boost::is_stateless</classname><F></code> is true. The construction of or copy to a Boost.Function object from a stateless function object will not cause exceptions to be thrown and will not allocate any storage. </para> </listitem> </itemizedlist> </para> </section> <header name="boost/function.hpp"> <namespace name="boost"> <class name="bad_function_call"> <inherit access="public"><classname>std::runtime_error</classname></inherit> <purpose>An exception type thrown when an instance of a <code>function</code> object is empty when invoked.</purpose> <constructor> <effects><simpara>Constructs a <code><classname>bad_function_call</classname></code> exception object.</simpara></effects> </constructor> </class> <class name="function_base"> <purpose>The common base class for all Boost.Function objects. Objects of type function_base may not be created directly.</purpose> <method-group name="capacity"> <method name="empty" cv="const"> <type>bool</type> <returns><simpara><code>false</code> if <code>this</code> has a target, and <code>true</code> otherwise.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </method> </method-group> <method-group name="target access"> <overloaded-method name="target"> <signature> <template> <template-type-parameter name="Functor"/> </template> <type>Functor*</type> </signature> <signature cv="const"> <template> <template-type-parameter name="Functor"/> </template> <type>const Functor*</type> </signature> <returns><simpara>If <code>this</code> stores a target of type <code>Functor</code>, returns the address of the target. Otherwise, returns the NULL pointer.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </overloaded-method> <method name="contains" cv="const"> <template> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"> <paramtype>const Functor&</paramtype> </parameter> <returns><simpara><code>true</code> if <code>this-><methodname>target</methodname><Functor>()</code> is non-NULL and <code><functionname>function_equal</functionname>(*(this->target<Functor>()), f)</code></simpara></returns> </method> <method name="target_type" cv="const"> <type>const std::type_info&</type> <returns><simpara><code>typeid</code> of the target function object, or <code>typeid(void)</code> if <code>this-><methodname>empty</methodname>()</code>.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </method> </method-group> </class> <class name="functionN"> <template> <template-type-parameter name="R"/> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> </template> <inherit access="public"><classname>function_base</classname></inherit> <purpose>A set of generalized function pointers that can be used for callbacks or wrapping function objects.</purpose> <description> <para>Class template <classname>functionN</classname> is actually a family of related classes <classname alt="functionN">function0</classname>, <classname alt="functionN">function1</classname>, etc., up to some implementation-defined maximum. In this context, <code>N</code> refers to the number of parameters.</para> </description> <typedef name="result_type"><type>R</type></typedef> <typedef name="argument_type"> <type>T1</type><purpose>If N == 1</purpose> </typedef> <typedef name="first_argument_type"> <type>T1</type> <purpose>If N == 2</purpose> </typedef> <typedef name="second_argument_type"> <type>T2</type> <purpose>If N == 2</purpose> </typedef> <typedef name="arg1_type"><type>T1</type></typedef> <typedef name="arg2_type"><type>T2</type></typedef> <typedef name="..."><type/></typedef> <typedef name="argN_type"><type>TN</type></typedef> <static-constant name="arity"> <type>int</type> <default>N</default> </static-constant> <struct name="sig"> <template> <template-type-parameter name="Args"/> </template> <purpose> <simpara><libraryname>Lambda</libraryname> library support</simpara> </purpose> <typedef name="type"><type>result_type</type></typedef> </struct> <constructor> <postconditions><simpara><code>this-><methodname>empty</methodname>()</code></simpara></postconditions> <throws><simpara>Will not throw.</simpara></throws> </constructor> <constructor> <parameter name="f"> <paramtype>const <classname>functionN</classname>&</paramtype> </parameter> <postconditions><simpara>Contains a copy of the <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code>.</simpara></postconditions> <throws><simpara>Will not throw unless copying the target of <code>f</code> throws.</simpara></throws> </constructor> <constructor> <parameter name="f"> <paramtype><classname>functionN</classname>&&</paramtype> </parameter> <requires><simpara>C++11 compatible compiler.</simpara></requires> <postconditions><simpara>Moves the value from <code>f</code> to <code>*this</code>. If the argument has its function object allocated on the heap, its buffer will be assigned to <code>*this</code> leaving argument empty.</simpara></postconditions> <throws><simpara>Will not throw unless argument has its function object allocated not on the heap and copying the target of <code>f</code> throws.</simpara></throws> </constructor> <constructor> <template> <template-type-parameter name="F"/> </template> <parameter name="f"><paramtype>F</paramtype></parameter> <requires><simpara>F is a function object Callable from <code>this</code>.</simpara></requires> <postconditions><simpara><code>*this</code> targets a copy of <code>f</code> if <code>f</code> is nonempty, or <code>this-><methodname>empty</methodname>()</code> if <code>f</code> is empty.</simpara></postconditions> </constructor> <constructor> <template> <template-type-parameter name="F"/> <template-type-parameter name="Allocator"/> </template> <parameter name="f"><paramtype>F</paramtype></parameter> <parameter name="alloc"><paramtype>Allocator</paramtype></parameter> <requires><simpara>F is a function object Callable from <code>this</code>, Allocator is an allocator. The copy constructor and destructor of Allocator shall not throw.</simpara></requires> <postconditions><simpara><code>*this</code> targets a copy of <code>f</code> if <code>f</code> is nonempty, or <code>this-><methodname>empty</methodname>()</code> if <code>f</code> is empty.</simpara></postconditions> <effects><simpara>If memory allocation is required, the given allocator (or a copy of it) will be used to allocate that memory.</simpara></effects> </constructor> <destructor> <effects><simpara>If <code>!this-><methodname>empty</methodname>()</code>, destroys the target of this.</simpara></effects> </destructor> <copy-assignment> <parameter name="f"> <paramtype>const <classname>functionN</classname>&</paramtype> </parameter> <postconditions><simpara>If copy construction does not throw, <code>*this</code> targets a copy of <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code>. If copy construction does throw, <code>this-><methodname>empty</methodname>()</code>.</simpara></postconditions> </copy-assignment> <copy-assignment> <parameter name="f"> <paramtype><classname>functionN</classname>&&</paramtype> </parameter> <requires><simpara>C++11 compatible compiler.</simpara></requires> <postconditions><simpara>Moves the value from <code>f</code> to <code>*this</code>. If the argument has its function object allocated on the heap, its buffer will be assigned to <code>*this</code> leaving argument empty.</simpara></postconditions> <throws><simpara>Will not throw unless argument has its function object allocated not on the heap and copying the target of <code>f</code> throws.</simpara></throws> </copy-assignment> <method-group name="modifiers"> <method name="swap"> <type>void</type> <parameter name="f"><paramtype>const <classname>functionN</classname>&</paramtype></parameter> <effects><simpara>Interchanges the targets of <code>*this</code> and <code>f</code>.</simpara></effects> </method> <method name="clear"> <type>void</type> <postconditions><simpara>this-><methodname>empty</methodname>()</simpara></postconditions> </method> </method-group> <method-group name="capacity"> <method name="empty" cv="const"> <type>bool</type> <returns><simpara><code>false</code> if <code>this</code> has a target, and <code>true</code> otherwise.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </method> <method name="conversion-operator" cv="const"> <type>safe_bool</type> <returns><simpara>A <code>safe_bool</code> that evaluates <code>false</code> in a boolean context when <code>this-><methodname>empty</methodname>()</code>, and <code>true</code> otherwise.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </method> <method name="operator!" cv="const"> <type>bool</type> <returns><simpara><code>this-><methodname>empty</methodname>()</code></simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </method> </method-group> <method-group name="target access"> <overloaded-method name="target"> <signature> <template> <template-type-parameter name="Functor"/> </template> <type>Functor*</type> </signature> <signature cv="const"> <template> <template-type-parameter name="Functor"/> </template> <type>const Functor*</type> </signature> <returns><simpara>If <code>this</code> stores a target of type <code>Functor</code>, returns the address of the target. Otherwise, returns the NULL pointer.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </overloaded-method> <method name="contains" cv="const"> <template> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"> <paramtype>const Functor&</paramtype> </parameter> <returns><simpara><code>true</code> if <code>this-><methodname>target</methodname><Functor>()</code> is non-NULL and <code><functionname>function_equal</functionname>(*(this->target<Functor>()), f)</code></simpara></returns> </method> <method name="target_type" cv="const"> <type>const std::type_info&</type> <returns><simpara><code>typeid</code> of the target function object, or <code>typeid(void)</code> if <code>this-><methodname>empty</methodname>()</code>.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </method> </method-group> <method-group name="invocation"> <method name="operator()" cv="const"> <type>result_type</type> <parameter name="a1"><paramtype>arg1_type</paramtype></parameter> <parameter name="a2"><paramtype>arg2_type</paramtype></parameter> <parameter><paramtype>...</paramtype></parameter> <parameter name="aN"><paramtype>argN_type</paramtype></parameter> <effects><simpara><code>f(a1, a2, ..., aN)</code>, where <code>f</code> is the target of <code>*this</code>.</simpara></effects> <returns><simpara>if <code>R</code> is <code>void</code>, nothing is returned; otherwise, the return value of the call to <code>f</code> is returned.</simpara></returns> <throws><simpara><code><classname>bad_function_call</classname></code> if <code>this-><methodname>empty</methodname>()</code>. Otherwise, may through any exception thrown by the target function <code>f</code>.</simpara></throws> </method> </method-group> <free-function-group name="specialized algorithms"> <function name="swap"> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> </template> <type>void</type> <parameter name="f1"><paramtype><classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> <parameter name="f2"><paramtype><classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> <effects><simpara><code>f1.<methodname>swap</methodname>(f2)</code></simpara></effects> </function> </free-function-group> <free-function-group name="comparison operators"> <overloaded-function name="operator=="> <signature> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"><paramtype>const <classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> <parameter name="g"><paramtype>Functor</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="g"><paramtype>Functor</paramtype></parameter> <parameter name="f"><paramtype>const <classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"><paramtype>const <classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> <parameter name="g"><paramtype><classname>reference_wrapper</classname><Functor></paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="g"><paramtype><classname>reference_wrapper</classname><Functor></paramtype></parameter> <parameter name="f"><paramtype>const <classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> <template-type-parameter name="U1"/> <template-type-parameter name="U2"/> <template-varargs/> <template-type-parameter name="UN"/> </template> <type>void</type> <parameter name="f1"><paramtype>const <classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> <parameter name="f2"><paramtype>const <classname>functionN</classname><U1, U2, ..., UN>&</paramtype></parameter> </signature> <returns><simpara>True when <code>f</code> stores an object of type <code>Functor</code> and one of the following conditions applies: <itemizedlist> <listitem><simpara><code>g</code> is of type <code><classname>reference_wrapper</classname><Functor></code> and <code>f.target<Functor>() == g.<methodname alt="reference_wrapper::get_pointer">get_pointer</methodname>()</code>.</simpara></listitem> <listitem><simpara><code>g</code> is not of type <code><classname>reference_wrapper</classname><Functor></code> and <code><functionname>function_equal</functionname>(*(f.target<Functor>()), g)</code>.</simpara></listitem> </itemizedlist> </simpara></returns> <notes><simpara><code><classname>functionN</classname></code> objects are not <conceptname>EqualityComparable</conceptname>.</simpara></notes> <rationale><simpara>The <code>safe_bool</code> conversion opens a loophole whereby two <code>functionN</code> instances can be compared via <code>==</code>, although this is not feasible to implement. The undefined <code>void operator==</code> closes the loophole and ensures a compile-time or link-time error.</simpara></rationale> </overloaded-function> <overloaded-function name="operator!="> <signature> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"><paramtype>const <classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> <parameter name="g"><paramtype>Functor</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="g"><paramtype>Functor</paramtype></parameter> <parameter name="f"><paramtype>const <classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"><paramtype>const <classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> <parameter name="g"><paramtype><classname>reference_wrapper</classname><Functor></paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="g"><paramtype><classname>reference_wrapper</classname><Functor></paramtype></parameter> <parameter name="f"><paramtype>const <classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="T1"/> <template-type-parameter name="T2"/> <template-varargs/> <template-type-parameter name="TN"/> <template-type-parameter name="U1"/> <template-type-parameter name="U2"/> <template-varargs/> <template-type-parameter name="UN"/> </template> <type>void</type> <parameter name="f1"><paramtype>const <classname>functionN</classname><T1, T2, ..., TN>&</paramtype></parameter> <parameter name="f2"><paramtype>const <classname>functionN</classname><U1, U2, ..., UN>&</paramtype></parameter> </signature> <returns><simpara>True when <code>f</code> does not store an object of type <code>Functor</code> or it stores an object of type <code>Functor</code> and one of the following conditions applies: <itemizedlist> <listitem><simpara><code>g</code> is of type <code><classname>reference_wrapper</classname><Functor></code> and <code>f.target<Functor>() != g.<methodname alt="reference_wrapper::get_pointer">get_pointer</methodname>()</code>.</simpara></listitem> <listitem><simpara><code>g</code> is not of type <code><classname>reference_wrapper</classname><Functor></code> and <code>!<functionname>function_equal</functionname>(*(f.target<Functor>()), g)</code>.</simpara></listitem> </itemizedlist> </simpara></returns> <notes><simpara><code><classname>functionN</classname></code> objects are not <conceptname>EqualityComparable</conceptname>.</simpara></notes> <rationale><simpara>The <code>safe_bool</code> conversion opens a loophole whereby two <code>functionN</code> instances can be compared via <code>!=</code>, although this is not feasible to implement. The undefined <code>void operator!=</code> closes the loophole and ensures a compile-time or link-time error.</simpara></rationale> </overloaded-function> </free-function-group> </class> <class name="function"> <template> <template-type-parameter name="Signature"> <purpose>Function type R (T1, T2, ..., TN)</purpose> </template-type-parameter> </template> <inherit access="public"><classname>functionN</classname><R, T1, T2, ..., TN></inherit> <purpose>A generalized function pointer that can be used for callbacks or wrapping function objects.</purpose> <description> <para>Class template <classname>function</classname> is a thin wrapper around the numbered class templates <classname alt="functionN">function0</classname>, <classname alt="functionN">function1</classname>, etc. It accepts a function type with N arguments and will will derive from <classname>functionN</classname> instantiated with the arguments it receives.</para> <para>The semantics of all operations in class template <classname>function</classname> are equivalent to that of the underlying <classname>functionN</classname> object, although additional member functions are required to allow proper copy construction and copy assignment of function objects.</para> </description> <typedef name="result_type"><type>R</type></typedef> <typedef name="argument_type"> <type>T1</type><purpose>If N == 1</purpose> </typedef> <typedef name="first_argument_type"> <type>T1</type> <purpose>If N == 2</purpose> </typedef> <typedef name="second_argument_type"> <type>T2</type> <purpose>If N == 2</purpose> </typedef> <typedef name="arg1_type"><type>T1</type></typedef> <typedef name="arg2_type"><type>T2</type></typedef> <typedef name="..."><type/></typedef> <typedef name="argN_type"><type>TN</type></typedef> <static-constant name="arity"> <type>int</type> <default>N</default> </static-constant> <struct name="sig"> <template> <template-type-parameter name="Args"/> </template> <purpose> <simpara><libraryname>Lambda</libraryname> library support</simpara> </purpose> <typedef name="type"><type>result_type</type></typedef> </struct> <constructor> <postconditions><simpara><code>this-><methodname>empty</methodname>()</code></simpara></postconditions> <throws><simpara>Will not throw.</simpara></throws> </constructor> <constructor> <parameter name="f"> <paramtype>const <classname>functionN</classname>&</paramtype> </parameter> <postconditions><simpara>Contains a copy of the <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code>.</simpara></postconditions> <throws><simpara>Will not throw unless copying the target of <code>f</code> throws.</simpara></throws> </constructor> <constructor> <parameter name="f"> <paramtype><classname>functionN</classname>&&</paramtype> </parameter> <requires><simpara>C++11 compatible compiler.</simpara></requires> <postconditions><simpara>Moves the value from <code>f</code> to <code>*this</code>. If the argument has its function object allocated on the heap, its buffer will be assigned to <code>*this</code> leaving argument empty.</simpara></postconditions> <throws><simpara>Will not throw unless argument has its function object allocated not on the heap and copying the target of <code>f</code> throws.</simpara></throws> </constructor> <constructor> <parameter name="f"> <paramtype>const <classname>function</classname>&</paramtype> </parameter> <postconditions><simpara>Contains a copy of the <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code>.</simpara></postconditions> <throws><simpara>Will not throw unless copying the target of <code>f</code> throws.</simpara></throws> </constructor> <constructor> <parameter name="f"> <paramtype><classname>function</classname>&&</paramtype> </parameter> <requires><simpara>C++11 compatible compiler.</simpara></requires> <postconditions><simpara>Moves the value from <code>f</code> to <code>*this</code>. If the argument has its function object allocated on the heap, its buffer will be assigned to <code>*this</code> leaving argument empty.</simpara></postconditions> <throws><simpara>Will not throw unless argument has its function object allocated not on the heap and copying the target of <code>f</code> throws.</simpara></throws> </constructor> <constructor> <template> <template-type-parameter name="F"/> </template> <parameter name="f"><paramtype>F</paramtype></parameter> <requires><simpara>F is a function object Callable from <code>this</code>.</simpara></requires> <postconditions><simpara><code>*this</code> targets a copy of <code>f</code> if <code>f</code> is nonempty, or <code>this-><methodname>empty</methodname>()</code> if <code>f</code> is empty.</simpara></postconditions> </constructor> <constructor> <template> <template-type-parameter name="F"/> <template-type-parameter name="Allocator"/> </template> <parameter name="f"><paramtype>F</paramtype></parameter> <parameter name="alloc"><paramtype>Allocator</paramtype></parameter> <requires><simpara>F is a function object Callable from <code>this</code>, Allocator is an allocator. The copy constructor and destructor of Allocator shall not throw.</simpara></requires> <postconditions><simpara><code>*this</code> targets a copy of <code>f</code> if <code>f</code> is nonempty, or <code>this-><methodname>empty</methodname>()</code> if <code>f</code> is empty.</simpara></postconditions> <effects><simpara>If memory allocation is required, the given allocator (or a copy of it) will be used to allocate that memory.</simpara></effects> </constructor> <destructor> <effects><simpara>If <code>!this-><methodname>empty</methodname>()</code>, destroys the target of <code>this</code>.</simpara></effects> </destructor> <copy-assignment> <parameter name="f"> <paramtype>const <classname>functionN</classname>&</paramtype> </parameter> <postconditions><simpara>If copy construction does not throw, <code>*this</code> targets a copy of <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code>. If copy construction does throw, <code>this-><methodname>empty</methodname>()</code>.</simpara></postconditions> </copy-assignment> <copy-assignment> <parameter name="f"> <paramtype><classname>functionN</classname>&&</paramtype> </parameter> <requires><simpara>C++11 compatible compiler.</simpara></requires> <postconditions><simpara>Moves the value from <code>f</code> to <code>*this</code>. If the argument has its function object allocated on the heap, its buffer will be assigned to <code>*this</code> leaving argument empty.</simpara></postconditions> <throws><simpara>Will not throw unless argument has its function object allocated not on the heap and copying the target of <code>f</code> throws.</simpara></throws> </copy-assignment> <copy-assignment> <parameter name="f"> <paramtype>const <classname>function</classname>&</paramtype> </parameter> <postconditions><simpara>If copy construction of the target of <code>f</code> does not throw, <code>*this</code> targets a copy of <code>f</code>'s target, if it has one, or is empty if <code>f.<methodname>empty</methodname>()</code>. </simpara></postconditions> <throws><simpara>Will not throw when the target of <code>f</code> is a stateless function object or a reference to the function object. If copy construction does throw, <code>this-><methodname>empty</methodname>()</code>.</simpara></throws> </copy-assignment> <copy-assignment> <parameter name="f"> <paramtype><classname>function</classname>&&</paramtype> </parameter> <requires><simpara>C++11 compatible compiler.</simpara></requires> <postconditions><simpara>Moves the value from <code>f</code> to <code>*this</code>. If the argument has its function object allocated on the heap, its buffer will be assigned to <code>*this</code> leaving argument empty.</simpara></postconditions> <throws><simpara>Will not throw unless argument has its function object allocated not on the heap and copying the target of <code>f</code> throws.</simpara></throws> </copy-assignment> <method-group name="modifiers"> <method name="swap"> <type>void</type> <parameter name="f"><paramtype>const <classname>function</classname>&</paramtype></parameter> <effects><simpara>Interchanges the targets of <code>*this</code> and <code>f</code>.</simpara></effects> </method> <method name="clear"> <type>void</type> <postconditions><simpara><code>this-><methodname>empty</methodname>()</code></simpara></postconditions> <throws><simpara>Will not throw.</simpara></throws> </method> </method-group> <method-group name="capacity"> <method name="empty" cv="const"> <type>bool</type> <returns><simpara><code>false</code> if <code>this</code> has a target, and <code>true</code> otherwise.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </method> <method name="conversion-operator" cv="const"> <type>safe_bool</type> <returns><simpara>A <code>safe_bool</code> that evaluates <code>false</code> in a boolean context when <code>this-><methodname>empty</methodname>()</code>, and <code>true</code> otherwise.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </method> <method name="operator!" cv="const"> <type>bool</type> <returns><simpara><code>this-><methodname>empty</methodname>()</code></simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </method> </method-group> <method-group name="target access"> <overloaded-method name="target"> <signature> <template> <template-type-parameter name="Functor"/> </template> <type>Functor*</type> </signature> <signature cv="const"> <template> <template-type-parameter name="Functor"/> </template> <type>const Functor*</type> </signature> <returns><simpara>If <code>this</code> stores a target of type <code>Functor</code>, returns the address of the target. Otherwise, returns the NULL pointer.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </overloaded-method> <method name="contains" cv="const"> <template> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"> <paramtype>const Functor&</paramtype> </parameter> <returns><simpara><code>true</code> if <code>this-><methodname>target</methodname><Functor>()</code> is non-NULL and <code><functionname>function_equal</functionname>(*(this->target<Functor>()), f)</code></simpara></returns> </method> <method name="target_type" cv="const"> <type>const std::type_info&</type> <returns><simpara><code>typeid</code> of the target function object, or <code>typeid(void)</code> if <code>this-><methodname>empty</methodname>()</code>.</simpara></returns> <throws><simpara>Will not throw.</simpara></throws> </method> </method-group> <method-group name="invocation"> <method name="operator()" cv="const"> <type>result_type</type> <parameter name="a1"><paramtype>arg1_type</paramtype></parameter> <parameter name="a2"><paramtype>arg2_type</paramtype></parameter> <parameter><paramtype>...</paramtype></parameter> <parameter name="aN"><paramtype>argN_type</paramtype></parameter> <effects><simpara><code>f(a1, a2, ..., aN)</code>, where <code>f</code> is the target of <code>*this</code>.</simpara></effects> <returns><simpara>if <code>R</code> is <code>void</code>, nothing is returned; otherwise, the return value of the call to <code>f</code> is returned.</simpara></returns> <throws><simpara><code><classname>bad_function_call</classname></code> if <code>this-><methodname>empty</methodname>()</code>. Otherwise, may through any exception thrown by the target function <code>f</code>.</simpara></throws> </method> </method-group> <free-function-group name="specialized algorithms"> <function name="swap"> <template> <template-type-parameter name="Signature"/> </template> <type>void</type> <parameter name="f1"><paramtype><classname>function</classname><Signature>&</paramtype></parameter> <parameter name="f2"><paramtype><classname>function</classname><Signature>&</paramtype></parameter> <effects><simpara><code>f1.<methodname>swap</methodname>(f2)</code></simpara></effects> </function> </free-function-group> <free-function-group name="comparison operators"> <overloaded-function name="operator=="> <signature> <template> <template-type-parameter name="Signature"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"><paramtype>const <classname>function</classname><Signature>&</paramtype></parameter> <parameter name="g"><paramtype>Functor</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="Signature"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="g"><paramtype>Functor</paramtype></parameter> <parameter name="f"><paramtype>const <classname>function</classname><Signature>&</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="Signature"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"><paramtype>const <classname>function</classname><Signature>&</paramtype></parameter> <parameter name="g"><paramtype><classname>reference_wrapper</classname><Functor></paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="Signature"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="g"><paramtype><classname>reference_wrapper</classname><Functor></paramtype></parameter> <parameter name="f"><paramtype>const <classname>function</classname><Signature>&</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="Signature1"/> <template-type-parameter name="Signature2"/> </template> <type>void</type> <parameter name="f1"><paramtype>const <classname>function</classname><Signature1>&</paramtype></parameter> <parameter name="f2"><paramtype>const <classname>function</classname><Signature2>&</paramtype></parameter> </signature> <returns><simpara>True when <code>f</code> stores an object of type <code>Functor</code> and one of the following conditions applies: <itemizedlist> <listitem><simpara><code>g</code> is of type <code><classname>reference_wrapper</classname><Functor></code> and <code>f.target<Functor>() == g.<methodname alt="reference_wrapper::get_pointer">get_pointer</methodname>()</code>.</simpara></listitem> <listitem><simpara><code>g</code> is not of type <code><classname>reference_wrapper</classname><Functor></code> and <code><functionname>function_equals</functionname>(*(f.target<Functor>()), g)</code>.</simpara></listitem> </itemizedlist> </simpara></returns> <notes><simpara><code><classname>function</classname></code> objects are not <conceptname>EqualityComparable</conceptname>.</simpara></notes> <rationale><simpara>The <code>safe_bool</code> conversion opens a loophole whereby two <code>function</code> instances can be compared via <code>==</code>, although this is not feasible to implement. The undefined <code>void operator==</code> closes the loophole and ensures a compile-time or link-time error.</simpara></rationale> </overloaded-function> <overloaded-function name="operator!="> <signature> <template> <template-type-parameter name="Signature"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"><paramtype>const <classname>function</classname><Signature>&</paramtype></parameter> <parameter name="g"><paramtype>Functor</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="Signature"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="g"><paramtype>Functor</paramtype></parameter> <parameter name="f"><paramtype>const <classname>function</classname><Signature>&</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="Signature"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="f"><paramtype>const <classname>function</classname><Signature>&</paramtype></parameter> <parameter name="g"><paramtype><classname>reference_wrapper</classname><Functor></paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="Signature"/> <template-type-parameter name="Functor"/> </template> <type>bool</type> <parameter name="g"><paramtype><classname>reference_wrapper</classname><Functor></paramtype></parameter> <parameter name="f"><paramtype>const <classname>function</classname><Signature>&</paramtype></parameter> </signature> <signature> <template> <template-type-parameter name="Signature1"/> <template-type-parameter name="Signature2"/> </template> <type>void</type> <parameter name="f1"><paramtype>const <classname>function</classname><Signature1>&</paramtype></parameter> <parameter name="f2"><paramtype>const <classname>function</classname><Signature2>&</paramtype></parameter> </signature> <returns><simpara>True when <code>f</code> does not store an object of type <code>Functor</code> or it stores an object of type <code>Functor</code> and one of the following conditions applies: <itemizedlist> <listitem><simpara><code>g</code> is of type <code><classname>reference_wrapper</classname><Functor></code> and <code>f.target<Functor>() != g.<methodname alt="reference_wrapper::get_pointer">get_pointer</methodname>()</code>.</simpara></listitem> <listitem><simpara><code>g</code> is not of type <code><classname>reference_wrapper</classname><Functor></code> and <code>!<functionname>function_equals</functionname>(*(f.target<Functor>()), g)</code>.</simpara></listitem> </itemizedlist> </simpara></returns> <notes><simpara><code><classname>function</classname></code> objects are not <conceptname>EqualityComparable</conceptname>.</simpara></notes> <rationale><simpara>The <code>safe_bool</code> conversion opens a loophole whereby two <code>function</code> instances can be compared via <code>!=</code>, although this is not feasible to implement. The undefined <code>void operator!=</code> closes the loophole and ensures a compile-time or link-time error.</simpara></rationale> </overloaded-function> </free-function-group> </class> </namespace> </header> <header name="boost/function_equal.hpp"> <namespace name="boost"> <function name="function_equal"> <template> <template-type-parameter name="F"/> <template-type-parameter name="G"/> </template> <type>bool</type> <parameter name="f"> <paramtype>const F&</paramtype> </parameter> <parameter name="g"> <paramtype>const G&</paramtype> </parameter> <purpose><simpara>Compare two function objects for equality.</simpara></purpose> <returns><simpara><code>f == g</code>.</simpara></returns> <throws><simpara>Only if <code>f == g</code> throws.</simpara></throws> </function> </namespace> </header> </library-reference>