.. Metafunctions/Arithmetic Operations//negate |60

negate

Synopsis

.. parsed-literal::

template<
      typename T
    >
struct negate
{
    typedef |unspecified| type;
};

Description

Returns the negative (additive inverse) of its argument.

Header

.. parsed-literal::

#include <boost/mpl/negate.hpp>
#include <boost/mpl/arithmetic.hpp>

Model of

|Numeric Metafunction|

Parameters

+---------------+---------------------------+-----------------------------------------------+ | Parameter | Requirement | Description | +===============+===========================+===============================================+ | T | |Integral Constant| | Operation's argument. | +---------------+---------------------------+-----------------------------------------------+

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

Expression semantics

For any |Integral Constant| c:

.. parsed-literal::

typedef negate<c>::type r; 

:Return type: |Integral Constant|.

:Semantics: Equivalent to

.. parsed-literal::

    typedef integral_c< c::value_type, ( -c::value ) > r;

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

.. parsed-literal::

typedef negate<c> r; 

:Return type: |Integral Constant|.

:Semantics: Equivalent to

.. parsed-literal::

    struct r : negate<c>::type {};

Complexity

Amortized constant time.

Example

.. parsed-literal::

typedef negate< int_<-10> >::type r;
BOOST_MPL_ASSERT_RELATION( r::value, ==, 10 );
BOOST_MPL_ASSERT(( is_same< r::value_type, int > ));

See also

|Arithmetic Operations|, |Numeric Metafunction|, |numeric_cast|, |plus|, |minus|, |times|

.. 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)