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      bool C
struct bool_
    // unspecified
    // ...

typedef bool_<true>  true_;
typedef bool_<false> false_;


A boolean Integral Constant wrapper.


#include <boost/mpl/bool.hpp>

Model of

Integral Constant


Parameter Requirement Description
C A boolean integral 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 integral constant c:

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


BOOST_MPL_ASSERT(( is_same< bool_<true>::value_type, bool > ));
BOOST_MPL_ASSERT(( is_same< bool_<true>, true_ > )); }
BOOST_MPL_ASSERT(( is_same< bool_<true>::type, bool_<true> > ));
BOOST_MPL_ASSERT_RELATION( bool_<true>::value, ==, true );
assert( bool_<true>() == true );

See also

Data Types, Integral Constant, int_, long_, integral_c