3rdParty/boost/1.78.0/libs/mpl/doc/src/refmanual/pair.rst
.. Data Types/Miscellaneous//pair |10
.. parsed-literal::
template<
typename T1
, typename T2
>
struct pair
{
typedef pair type;
typedef T1 first;
typedef T2 second;
};
A transparent holder for two arbitrary types.
.. parsed-literal::
#include <boost/mpl/pair.hpp>
Count a number of elements in the sequence together with a number of negative elements among these.
.. parsed-literal::
typedef fold<
vector_c<int,-1,0,5,-7,-2,4,5,7>
, pair< int_<0>, int_<0> >
, pair<
next< first<_1> >
, if_<
less< _2, int_<0> >
, next< second<_1> >
, second<_1>
>
>
>::type p;
BOOST_MPL_ASSERT_RELATION( p::first::value, ==, 8 );
BOOST_MPL_ASSERT_RELATION( p::second::value, ==, 3 );
|Data Types|, |Sequences|, |first|, |second|
.. copyright:: Copyright 2001-2009 Aleksey Gurtovoy and David Abrahams Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)