...one of the most highly
regarded and expertly designed C++ library projects in the
world.

— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards

Front Page / Metafunctions / Arithmetic Operations / negate |

Returns the negative (additive inverse) of its argument.

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

Parameter | Requirement | Description |
---|---|---|

T |
Integral Constant | Operation's argument. |

[*Note:* The requirements listed in this specification
are the ones imposed by the default implementation. See Numeric Metafunction concept
for the details on how to provide an implementation for a user-defined numeric type
that does not satisfy the Integral Constant requirements. — *end note*]

For any Integral Constant `c`:

typedef negate<c>::type r;

Return type: | |
---|---|

Semantics: | Equivalent to typedef integral_c< c::value_type, ( -c::value ) > r; |

typedef negate<c> r;

Return type: | |
---|---|

Semantics: | Equivalent to struct r : negate<c>::type {}; |

Amortized constant time.

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