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count
Description

Returns the number of elements of a given type within a sequence.

Synopsis
template<
    typename Sequence,
    typename T
    >
typename result_of::count<Sequence, T>::type count(
    Sequence const& seq, T const& t);

Table 1.54. Parameters

Parameter

Requirement

Description

seq

A model of Forward Sequence, e == t must be a valid expression, convertible to bool, for each element e in seq

The sequence to search

T

Any type

The type to count


Expression Semantics
count(seq, t);

Return type: int

Semantics: Returns the number of elements of type T and equal to t in seq.

Complexity

Linear. At most result_of::size<Sequence>::value comparisons.

Header
#include <boost/fusion/algorithm/query/count.hpp>
#include <boost/fusion/include/count.hpp>
Example
const vector<double,int,int> vec(1.0,2,3);
assert(count(vec,2) == 1);

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