Trait

Description

Trait invocation/composition.

Modules
	Invocation
	Trait invocation.
	Composition
	Trait composition.
	lazy

Classes
struct	meta::id< T >
	A trait that always returns its argument T. Also, a Callable that always returns T. More...

Typedefs
template<class T >
using	meta::alignof_ = meta::size_t< alignof(T)>
	An alias that computes the alignment required for any instance of the type T. More...
template<typename T >
using	meta::id_t = _t< id< T > >
	An alias for type T. Useful in non-deduced contexts.
template<typename T , template< typename... > class C>
using	meta::is = _t< detail::is_< T, C > >
	is More...
template<typename T >
using	meta::is_callable = _t< detail::is_callable_< T > >
	An alias for std::true_type if T::invoke exists and names a class template or alias template; otherwise, it's an alias for std::false_type.
template<typename T >
using	meta::is_trait = _t< detail::is_trait_< T > >
	An alias for std::true_type if T::type exists and names a type; otherwise, it's an alias for std::false_type.
template<typename T >
using	meta::is_valid = detail::is_valid_< T >
	For testing whether a deferred computation will succeed in a let or a lambda.
template<typename... Ts>
using	meta::lambda = if_c<(sizeof...(Ts) > 0), detail::lambda_< list< Ts... > >>
	For creating anonymous Callables. More...
template<typename... As>
using	meta::let = _t< _t< detail::let_< As... > >>
	A lexically scoped expression with local variables. More...
template<typename F >
using	meta::not_fn = compose< quote< not_ >, F >
	Logically negate the result of Callable F.
template<class T >
using	meta::sizeof_ = meta::size_t< sizeof(T)>
	An alias that computes the size of the type T. More...
template<typename... >
using	meta::void_ = void
	An alias for void.

Typedef Documentation

alignof_

template<class T >

using meta::alignof_ = typedef meta::size_t<alignof(T)>

#include <meta/meta.hpp>

An alias that computes the alignment required for any instance of the type T.

Complexity

.

is

template<typename T , template< typename... > class C>

using meta::is = typedef _t<detail::is_<T, C> >

#include <meta/meta.hpp>

is

Test whether a type T is an instantiation of class template C.

lambda

template<typename... Ts>

using meta::lambda = typedef if_c<(sizeof...(Ts) > 0), detail::lambda_<list<Ts...> >>

#include <meta/meta.hpp>

For creating anonymous Callables.

using L = lambda<_a, _b, std::pair<_b, std::pair<_a, _a>>>;
using P = invoke<L, int, short>;
static_assert(std::is_same<P, std::pair<short, std::pair<int, int>>>::value,
"");

let

template<typename... As>

using meta::let = typedef _t<_t<detail::let_<As...> >>

#include <meta/meta.hpp>

A lexically scoped expression with local variables.

template <typename T, typename List>
using find_index_ = let<
    var<_a, List>,
    var<_b, lazy::find<_a, T>>,
    lazy::if_<
        std::is_same<_b, list<>>,
        meta::npos,
        lazy::minus<lazy::size<_a>, lazy::size<_b>>>>;
static_assert(find_index_<int, list<short, int, float>>{} == 1, "");
static_assert(find_index_<double, list<short, int, float>>{} ==
meta::npos{}, "");

sizeof_

template<class T >

using meta::sizeof_ = typedef meta::size_t<sizeof(T)>

#include <meta/meta.hpp>

An alias that computes the size of the type T.

Complexity

.