std::experimental::is_simd, std::experimental::is_simd_mask
From cppreference.com
| Defined in header <experimental/simd>
|
||
template< class T >
struct is_simd;
|
(1) | (parallelism TS v2) |
template< class T >
struct is_simd_mask;
|
(2) | (parallelism TS v2) |
1) If
T is a specialization of the simd class template, provides the member constant value equal true. For any other type, value is false.2) If
T is a specialization of the simd_mask class template, provides the member constant value equal true. For any other type, value is false.Template parameters
| T | - | a type to check |
Helper variable template
template< class T >
constexpr bool is_simd_v = is_simd<T>::value;
|
(parallelism TS v2) | |
template< class T >
constexpr bool is_simd_mask_v = is_simd_mask<T>::value;
|
(parallelism TS v2) | |
Inherited from std::integral_constant
Member constants
value [static] |
true if T is a simd/simd_mask type, false otherwise (public static member constant) |
Member functions
operator bool |
converts the object to bool, returns value (public member function) |
operator() (C++14) |
returns value (public member function) |
Member types
Notes
is_simd_v<T> is necessary but not sufficient for testing whether T can be used as a SIMD type. For example, is_simd_v<simd<bool>> is true, even though bool is not included in the permissible vectorizable types. The missing condition is std::is_constructible_v<T>, which is false for simd<bool>.
Example
Run this code
#include <experimental/simd>
#include <iostream>
#include <string_view>
namespace stdx = std::experimental;
template<typename T>
void test_simd(std::string_view type_name)
{
std::cout << std::boolalpha
<< "Type: " << type_name << '\n'
<< " is_simd: " << stdx::is_simd_v<T> << '\n'
<< " is_constructible: " << std::is_constructible_v<T> << '\n';
}
template<typename T>
void test_simd_mask(std::string_view type_name)
{
std::cout << std::boolalpha
<< "Type: " << type_name << '\n'
<< " is_simd_mask: " << stdx::is_simd_mask_v<T> << '\n'
<< " is_constructible: " << std::is_constructible_v<T> << "\n\n";
}
int main()
{
test_simd<int>("int");
test_simd_mask<int>("int");
test_simd<stdx::simd<float>>("simd<float>");
test_simd_mask<stdx::simd_mask<float>>("simd_mask<float>");
test_simd<stdx::simd<bool>>("simd<bool>");
test_simd_mask<stdx::simd_mask<bool>>("simd_mask<bool>");
}
Output:
Type: int
is_simd: false
is_constructible: true
Type: int
is_simd_mask: false
is_constructible: true
Type: simd<float>
is_simd: true
is_constructible: true
Type: simd_mask<float>
is_simd_mask: true
is_constructible: true
Type: simd<bool>
is_simd: true
is_constructible: false
Type: simd_mask<bool>
is_simd_mask: true
is_constructible: false