|  | 
| template<typename... Bs> | 
| using | meta::and_ = _t< detail::_and_< Bs... > > | 
|  | Logically AND together all the integral constant-wrapped Boolean parameters, with short-circuiting. 
 | 
|  | 
| template<bool If, typename Then , typename Else  = void> | 
| using | meta::conditional_t = typename detail::_cond< If >::template invoke< Then, Else > | 
|  | Select one type or another depending on a compile-time Boolean. 
 | 
|  | 
| template<typename... Args> | 
| using | meta::if_ = _t< detail::_if_< Args... > > | 
|  | Select one type or another depending on a compile-time Boolean. 
 | 
|  | 
| template<bool If, typename... Args> | 
| using | meta::if_c = _t< detail::_if_< bool_< If >, Args... > > | 
|  | Select one type or another depending on a compile-time Boolean. 
 | 
|  | 
| template<integral B> | 
| using | meta::not_ = not_c< B::type::value > | 
|  | Logically negate the integral constant-wrapped Boolean parameter. 
 | 
|  | 
| template<bool B> | 
| using | meta::not_c = bool_<!B > | 
|  | Logically negate the Boolean parameter. 
 | 
|  | 
| template<typename... Bs> | 
| using | meta::or_ = _t< detail::_or_< Bs... > > | 
|  | Logically OR together all the integral constant-wrapped Boolean parameters, with short-circuiting. 
 | 
|  | 
| template<integral ... Bs> | 
| using | meta::strict_and_ = and_c< Bs::type::value... > | 
|  | Logically AND together all the integral constant-wrapped Boolean parameters, without short-circuiting. 
 | 
|  | 
| template<integral ... Bs> | 
| using | meta::strict_or_ = or_c< Bs::type::value... > | 
|  | Logically OR together all the integral constant-wrapped Boolean parameters, without short-circuiting. 
 | 
|  | 
Logical operations.