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 2017. The current version is 1.89.0.

size

size

Description

Returns the result type of size.

Synopsis

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

Table 1.27. Parameters

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

Expression Semantics

result_of::size<Seq>::type

Return type: An MPL Integral Constant.

Semantics: Returns the number of elements in Seq.

Header

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

Example

typedef vector<int,float,char> vec;
typedef result_of::size<vec>::type size_mpl_integral_constant;
BOOST_MPL_ASSERT_RELATION(size_mpl_integral_constant::value, ==, 3);