remove.rst

C++的一个好库。。。现在很流行

.. Algorithms/Transformation Algorithms//remove |60

remove
======

Synopsis
--------

.. parsed-literal::
    
    template<
          typename Sequence
        , typename T
        , typename In = |unspecified|
        >
    struct remove
    {
        typedef |unspecified| type;
    };


Description
-----------

Returns a new sequence that contains all elements from |begin/end<Sequence>|
range except those that are identical to ``T``.

.. Returns a copy of the original sequence with all elements identical to ``T``
   removed.

|transformation algorithm disclaimer|


Header
------

.. parsed-literal::
    
    #include <boost/mpl/remove.hpp>


Model of
--------

|Reversible Algorithm|


Parameters
----------

+---------------+-----------------------------------+-------------------------------+
| Parameter     | Requirement                       | Description                   |
+===============+===================================+===============================+
| ``Sequence``  | |Forward Sequence|                | An original sequence.         |
+---------------+-----------------------------------+-------------------------------+
| ``T``         | Any type                          | A type to be removed.         |
+---------------+-----------------------------------+-------------------------------+
| ``In``        | |Inserter|                        | An inserter.                  |
+---------------+-----------------------------------+-------------------------------+


Expression semantics
--------------------

|Semantics disclaimer...| |Reversible Algorithm|.

For any |Forward Sequence| ``s``, an |Inserter| ``in``, and arbitrary type ``x``:


.. parsed-literal::

    typedef remove<s,x,in>::type r; 

:Return type:
    A type.

:Semantics:
    Equivalent to 

    .. parsed-literal::
    
        typedef remove_if< s,is_same<_,x>,in >::type r;


Complexity
----------

Linear. Performs exactly ``size<s>::value`` comparisons for equality, and at 
most ``size<s>::value`` insertions.


Example
-------

.. parsed-literal::
    
    typedef vector<int,float,char,float,float,double>::type types;
    typedef remove< types,float >::type result;

    BOOST_MPL_ASSERT(( equal< result, vector<int,char,double> > ));


See also
--------

|Transformation Algorithms|, |Reversible Algorithm|, |reverse_remove|, |remove_if|, |copy|, |replace|