Boost C++ Libraries

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equal_to

Description

Returns a true-valued MPL Integral Constant if I and J are equal.

Synopsis

template<
    typename I,
    typename J
    >
struct equal_to
{
    typedef unspecified type;
};

Table 1.16. Parameters

Parameter	Requirement	Description
`I`, `J`	Any fusion iterators	Operation's arguments

Expression Semantics

result_of::equal_to<I, J>::type

Return type: A model of MPL Integral Constant.

Semantics: Returns boost::mpl::true_ if I and J are iterators to the same position. Returns boost::mpl::false_ otherwise.

Header

#include <boost/fusion/iterator/equal_to.hpp>
#include <boost/fusion/include/equal_to.hpp>

Example

typedef vector<int,double> vec;
typedef result_of::begin<vec>::type first;
typedef result_of::end<vec>::type last;
BOOST_MPL_ASSERT((result_of::equal_to<first, first>));
BOOST_MPL_ASSERT_NOT((result_of::equal_to<first,last>));