Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

This is an older version of Boost and was released in 2014. The current version is 1.89.0.

front

front

Description

Returns the result type of front.

Synopsis

template<typename Seq>
struct front
{
    typedef unspecified type;
};

Table 1.26. Parameters

Parameter	Requirement	Description
`Seq`	A model of Forward Sequence	Argument sequence

Expression Semantics

result_of::front<Seq>::type

Return type: Any type

Semantics: The type returned by dereferencing an iterator to the first element in Seq. Equivalent to result_of::deref<result_of::begin<Seq>::type>::type.

Header

#include <boost/fusion/sequence/intrinsic/front.hpp>
#include <boost/fusion/include/front.hpp>

Example

typedef vector<int,char> vec;
BOOST_MPL_ASSERT((boost::is_same<result_of::front<vec>::type, int&>));