Type traits

Detailed Description

Type traits for SIMD related types and functions.

Using EVE types and functions may require information about some properties of the processed types that are accessible through the following traits.

Convenience header:

#include <eve/traits.hpp> 

Classes
struct	eve::abi< Type, Lanes >
	Find proper ABI for Type/Lanes pair. More...
struct	eve::as< T >
	Lightweight type-wrapper. More...
struct	eve::as_element< T >
	Lightweight type-wrapper over element type. More...
struct	eve::cardinal< Type >
	Computes the cardinal of a given type. More...
struct	eve::common_compatible< Ts >
	Computes the type compatible with a list of values. More...
struct	eve::common_type< Ts >
	Computes a type that can represent all values in a list of types. More...
struct	eve::comparisons< T >
	Extension point for ordering and equality computation. More...
struct	eve::element_type< T >
	Extracts the scalar part of a type. More...
struct	eve::underlying_type< Ts >
	Computes the most scalar type associated with a type. More...

Concepts
concept	eve::same_lanes_or_scalar
	Checks that all types Ts are either scalar or share a common number of lanes.
concept	eve::same_lanes_or_scalar_tuple
	Checks that all types within a product type are either scalar or share a common number of lanes.
concept	eve::same_lanes
	Checks that all SIMD types Ts share a common number of lanes.
concept	eve::same_types
	Checks that all types Ts are scalars of a single type U or simd_values sharing the same lane count and of element type U.
concept	eve::same_types_tuple
	Checks that all types within a product type are scalars of a single type U or simd_values sharing the same lane count and of element type U.

Typedefs
template<typename T>
using	eve::iterator_cardinal_t = decltype(_::iterator_cardinal_impl<T>())
	A meta-function that returns a cardinal for a relaxed iterator/range. If T defines a nested static function iterator_cardinal() (which should return eve::fixed).
template<typename... Ts>
using	eve::max_lanes_t = fixed<max_lanes_v<Ts...>>
	The cardinal type of the maximum lane count of given wide or scalar types.
template<typename T>
using	eve::value_type_t = typename decltype(_::value_type_impl<T>())::type
	A meta function for getting an associated value_type for a relaxed iterator/range.
template<typename T>
using	eve::wide_value_type_t = as_wide_t<value_type_t<T>, iterator_cardinal_t<T>>

Variables
template<typename... Ts>
constexpr auto	eve::max_lanes_v = _::compute_max_lanes<Ts...>()
	A meta function for getting a maximum lane count of given wide or scalar types.
template<typename T>
constexpr std::size_t	eve::max_scalar_size_v
	A meta function for getting a maximum size of scalar.

Typedef Documentation

iterator_cardinal_t

template<typename T>

using eve::iterator_cardinal_t = decltype(_::iterator_cardinal_impl<T>())

A meta-function that returns a cardinal for a relaxed iterator/range. If T defines a nested static function iterator_cardinal() (which should return eve::fixed).

Template Parameters

T	Type to process

• returns it's return type. Otherwise returns expected_cardinal_t<value_type_t<T>>.

NOTE: for aligned_ptr we return expected_cardinal.

Required header: #include <eve/traits/iterator_cardinal.hpp>, #include <eve/traits.hpp>

template<typename T>
inline constexpr auto iterator_cardinal_v = iterator_cardinal<T>::value;

max_lanes_t

template<typename... Ts>

using eve::max_lanes_t = fixed<max_lanes_v<Ts...>>

The cardinal type of the maximum lane count of given wide or scalar types.

Template Parameters

Ts	Types to process

value_type_t

template<typename T>

using eve::value_type_t = typename decltype(_::value_type_impl<T>())::type

A meta function for getting an associated value_type for a relaxed iterator/range.

Template Parameters

T	Type to process

value_type_t<T> is computed as follows:

• If T has begin/end - value_type_t for return type of begin
• If T is std::iterator -> returns iterator_traits<T>::value_type
• If T has nested value_type -> returns it
• If T is a product type and all elements have value_type_t defined for them -
• kumi::tuple for the individual product types.
• Otherwise it's undefined.

Template Parameters

T	Type to process

Required header: #include <eve/traits.hpp>

wide_value_type_t

template<typename T>

using eve::wide_value_type_t = as_wide_t<value_type_t<T>, iterator_cardinal_t<T>>

Template Parameters

T	Type to process

Required header: #include <eve/traits/wide_value_type.hpp>, #include <eve/traits.hpp>

template<typename T>
using wide_value_type_t = as_wide_t<value_type_t<T>, iterator_cardinal_t<T>>

Variable Documentation

max_lanes_v

template<typename... Ts>

auto eve::max_lanes_v = _::compute_max_lanes<Ts...>()

inlineconstexpr

A meta function for getting a maximum lane count of given wide or scalar types.

Template Parameters

Ts	Types to process

max_scalar_size_v

template<typename T>

std::size_t eve::max_scalar_size_v

constexpr

Initial value:

= kumi::max_flat( kumi::as_tuple_t<T>{}
                , [](auto m) { return sizeof(m); }
                )

A meta function for getting a maximum size of scalar.

Template Parameters

T	Type to process

   For a product type returns max size of individual fields.
   Otherwise returns sizeof(T)

Required header: #include <eve/traits/max_scalar_size.hpp>, #include <eve/traits.hpp>