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|
.. Metafunctions/Bitwise Operations//shift_right
shift_right
===========
Synopsis
--------
.. parsed-literal::
template<
typename T
, typename Shift
>
struct shift_right
{
typedef |unspecified| type;
};
Description
-----------
Returns the result of bitwise *shift right* (``>>``) operation on ``T``.
Header
------
.. parsed-literal::
#include <boost/mpl/shift_right.hpp>
#include <boost/mpl/bitwise.hpp>
Model of
--------
|Numeric Metafunction|
Parameters
----------
+---------------+-------------------------------+---------------------------+
| Parameter | Requirement | Description |
+===============+===============================+===========================+
| ``T`` | |Integral Constant| | A value to shift. |
+---------------+-------------------------------+---------------------------+
| ``Shift`` | Unsigned |Integral Constant| | A shift distance. |
+---------------+-------------------------------+---------------------------+
|Note:| |numeric metafunction note| |-- end note|
Expression semantics
--------------------
For arbitrary |Integral Constant| ``c`` and unsigned |Integral Constant| ``shift``:
.. parsed-literal::
typedef shift_right<c,shift>::type r;
:Return type:
|Integral Constant|.
:Semantics:
Equivalent to
.. parsed-literal::
typedef integral_c<
c::value_type
, ( c::value >> shift::value )
> r;
.. ..........................................................................
.. parsed-literal::
typedef shift_right<c,shift> r;
:Return type:
|Integral Constant|.
:Semantics:
Equivalent to
.. parsed-literal::
struct r : shift_right<c,shift>::type {};
Complexity
----------
Amortized constant time.
Example
-------
.. parsed-literal::
typedef integral_c<unsigned,0> u0;
typedef integral_c<unsigned,1> u1;
typedef integral_c<unsigned,2> u2;
typedef integral_c<unsigned,8> u8;
BOOST_MPL_ASSERT_RELATION( (shift_right<u0,u0>::value), ==, 0 );
BOOST_MPL_ASSERT_RELATION( (shift_right<u1,u0>::value), ==, 1 );
BOOST_MPL_ASSERT_RELATION( (shift_right<u1,u1>::value), ==, 0 );
BOOST_MPL_ASSERT_RELATION( (shift_right<u2,u1>::value), ==, 1 );
BOOST_MPL_ASSERT_RELATION( (shift_right<u8,u1>::value), ==, 4 );
See also
--------
|Bitwise Operations|, |Numeric Metafunction|, |numeric_cast|, |shift_left|, |bitand_|
.. 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)
|
