char_

Synopsis

template<
      char N
    >
struct char_
{
    // unspecified
    // ...
};

Description

An Integral Constant wrapper for char.

Header

#include <boost/mpl/char.hpp>

Model of

Integral Constant

Parameters

Parameter	Requirement	Description
`N`	A character constant	A value to wrap.

Expression semantics

The semantics of an expression are defined only where they differ from, or are not defined in Integral Constant.

For arbitrary character constant c:

Expression	Semantics
`char_<c>`	An Integral Constant `x` such that `x::value == c` and `x::value_type` is identical to `char`.

Example

typedef char_<'c'> c;

BOOST_MPL_ASSERT(( is_same< c::value_type, char > ));
BOOST_MPL_ASSERT(( is_same< c::type, c > ));
BOOST_MPL_ASSERT(( is_same< next< c >::type, char_<'d'> > ));
BOOST_MPL_ASSERT(( is_same< prior< c >::type, char_<'b'> > ));
BOOST_MPL_ASSERT_RELATION( (c::value), ==, 'c' );
assert( c() == 'c' );