Subject: [Boost-commit] svn:boost r66973 - trunk/libs/bind
From: marshall_at_[hidden]
Date: 2010-12-02 08:17:14
Author: marshall
Date: 2010-12-02 08:17:09 EST (Thu, 02 Dec 2010)
New Revision: 66973
URL: http://svn.boost.org/trac/boost/changeset/66973
Log:
Doc patch; refs #4532
Text files modified:
trunk/libs/bind/bind.html | 43 ++++++++++++++++++++++++++++++++++++++++
1 files changed, 43 insertions(+), 0 deletions(-)
Modified: trunk/libs/bind/bind.html
==============================================================================
--- trunk/libs/bind/bind.html (original)
+++ trunk/libs/bind/bind.html 2010-12-02 08:17:09 EST (Thu, 02 Dec 2010)
@@ -61,6 +61,7 @@
bind<R>(f, ...)</A></h4>
<h4 style="MARGIN-LEFT: 40pt">Binding a nonstandard function</h4>
<h4 style="MARGIN-LEFT: 40pt">Binding an overloaded function</h4>
+ <h4 style="MARGIN-LEFT: 40pt">Modeling STL function object concepts</h4>
<h4 style="MARGIN-LEFT: 40pt">const in signatures</h4>
<h4 style="MARGIN-LEFT: 40pt"><A href="#err_msvc_using">MSVC specific: using
boost::bind;</A></h4>
@@ -585,6 +586,48 @@
boost::bind( get, _1 );
}
</pre>
+ <h3><a name="err_modeling_stl_function_object_concepts">Modeling STL function object concepts</a></h3>
+ <p>The function objects that are produced by <b>boost::bind</b> do not model the
+ STL Unary Function or
+ Binary Function concepts,
+ even when the function objects are unary or binary operations, because the function object
+ types are missing public typedefs <tt>result_type</tt> and <tt>argument_type</tt> or
+ <tt>first_argument_type</tt> and <tt>second_argument_type</tt>. In cases where these
+ typedefs are desirable, however, the utility function <tt>make_adaptable</tt>
+ can be used to adapt unary and binary function objects to these concepts. This allows
+ unary and binary function objects resulting from <b>boost::bind</b> to be combined with
+ STL templates such as std::unary_negate
+ and std::binary_negate.</p>
+
+ <p>The <tt>make_adaptable</tt> function is defined in <boost/bind/make_adaptable.hpp>,
+ which must be included explicitly in addition to <boost/bind.hpp>:</p>
+ <pre>
+#include <boost/bind/make_adaptable.hpp>
+
+template <class R, class F> <i>unspecified-type</i> make_adaptable(F f);
+
+template<class R, class A1, class F> <i>unspecified-unary-functional-type</i> make_adaptable(F f);
+
+template<class R, class A1, class A2, class F> <i>unspecified-binary-functional-type</i> make_adaptable(F f);
+
+template<class R, class A1, class A2, class A3, class F> <i>unspecified-ternary-functional-type</i> make_adaptable(F f);
+
+template<class R, class A1, class A2, class A3, class A4, class F> <i>unspecified-4-ary-functional-type</i> make_adaptable(F f);
+ </pre>
+
+ <p>This example shows how to use <tt>make_adaptable</tt> to make a predicate for "is not a space":</p>
+ <pre>typedef char char_t;
+std::locale loc("");
+const std::ctype<char_t>& ct = std::use_facet<std::ctype<char_t> >(loc);
+
+auto isntspace = std::not1( boost::make_adaptable<bool, char_t>( boost::bind(&std::ctype<char_t>::is, &ct, std::ctype_base::space, _1) ) );
+</pre>
+
+ <p>In this example, <b>boost::bind</b> creates the "is a space" (unary) predicate.
+ It is then passed to <tt>make_adaptable</tt> so that a function object modeling
+ the Unary Function concept can be created, serving as the argument to
+ std::not1.</p>
+
<h3><a name="err_const_arg"><b>const</b> in signatures</a></h3>
<p>Some compilers, including MSVC 6.0 and Borland C++ 5.5.1, have problems with the
top-level <b>const</b> in function signatures: