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Description

Returns the first element in the sequence.

Synopsis
template <typename Sequence>
typename result_of::front<Sequence>::type
front(Sequence& seq);

template <typename Sequence>
typename result_of::front<Sequence const>::type
front(Sequence const& seq);
Parameters

Parameter

Requirement

Description

seq

Model of Forward Sequence

The sequence we wish to investigate.

Expression Semantics
front(seq);

Return type: Returns a reference to the first element in the sequence seq if seq is mutable and e = o, where e is the first element in the sequence, is a valid expression. Else, returns a type convertable to the first element in the sequence.

Precondition: empty(seq) == false

Semantics: Returns the first element in the sequence.

Header
#include <boost/fusion/sequence/intrinsic/front.hpp>
#include <boost/fusion/include/front.hpp>
Example
vector<int, int, int> v(1, 2, 3);
assert(front(v) == 1);

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