.. Metafunctions/Comparisons//less |10

less

Synopsis

.. parsed-literal::

template<
      typename T1
    , typename T2
    >
struct less
{
    typedef |unspecified| type;
};

Description

Returns a true-valued |Integral Constant| if T1 is less than T2.

Header

.. parsed-literal::

#include <boost/mpl/less.hpp>
#include <boost/mpl/comparison.hpp>

Model of

|Numeric Metafunction|

Parameters

+---------------+---------------------------+-----------------------------------------------+ | Parameter | Requirement | Description | +===============+===========================+===============================================+ | T1, T2| |Integral Constant| | Operation's arguments. | +---------------+---------------------------+-----------------------------------------------+

|Note:| |numeric metafunction note| |-- end note|

Expression semantics

For any |Integral Constant|\ s c1 and c2:

.. parsed-literal::

typedef less<c1,c2>::type r; 

:Return type: |Integral Constant|.

:Semantics: Equivalent to

.. parsed-literal::

    typedef bool_< (c1::value < c2::value) > r;

.. ..........................................................................

.. parsed-literal::

typedef less<c1,c2> r; 

:Return type: |Integral Constant|.

:Semantics: Equivalent to

.. parsed-literal::

    struct r : less<c1,c2>::type {};

Complexity

Amortized constant time.

Example

.. parsed-literal::

BOOST_MPL_ASSERT(( less< int_<0>, int_<10> > ));
BOOST_MPL_ASSERT_NOT(( less< long_<10>, int_<0> > ));
BOOST_MPL_ASSERT_NOT(( less< long_<10>, int_<10> > ));

See also

|Comparisons|, |Numeric Metafunction|, |numeric_cast|, |less_equal|, |greater|, |equal|

.. 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)