Boost C++ Libraries

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deref

Description

Returns the type that will be returned by dereferencing an iterator.

Synposis

template<
    typename I
    >
struct deref
{
    typedef unspecified type;
};

Table 1.12. Parameters

Parameter	Requirement	Description
`I`	Model of Forward Iterator	Operation's argument

Expression Semantics

result_of::deref<I>::type

Return type: Any type

Semantics: Returns the result of dereferencing an iterator of type I.

Header

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

Example

typedef vector<int,int&> vec;
typedef const vec const_vec;
typedef result_of::begin<vec>::type first;
typedef result_of::next<first>::type second;

typedef result_of::begin<const_vec>::type const_first;
typedef result_of::next<const_first>::type const_second;

BOOST_MPL_ASSERT((boost::is_same<result_of::deref<first>::type, int&>));
BOOST_MPL_ASSERT((boost::is_same<result_of::deref<second>::type, int&>));