Boost C++ Libraries

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value_at
Description

Returns the actual type at a given index from the Sequence.

Synopsis
template<
    typename Seq,
    typename N>
struct value_at
{
    typedef unspecified type;
};

Table 1.27. Parameters

Parameter

Requirement

Description

Seq

A model of Forward Sequence

Argument sequence

N

An MPL Integral Constant

Index of element

Expression Semantics
result_of::value_at<Seq, N>::type

Return type: Any type.

Semantics: Returns the actual type at the Nth element of Seq.

/sequence/intrinsic/value_at.hpp>

Example
typedef vector<int,float,char> vec;
BOOST_MPL_ASSERT((boost::is_same<result_of::value_at<vec, boost::mpl::int_<1> >::type, float>));

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