NAME

std::experimental::simd_abi::deduce - std::experimental::simd_abi::deduce

Synopsis

Defined in header <experimental/simd>
template < class T, std::size_t N, class ...Abis > (parallelism TS v2)
struct deduce;

The type deduce<T, N, Abis...>::type is present if and only if:

* T is a vectorizable type,
* simd_abi::fixed_size<N> is supported, and
* every type in Abis... is an ABI tag

Let DA denote deduce<T, N, Abis...>::type when it presents, then

* simd_size_v<T, DA> == N
* simd<T, DA> is default constructible, i.e. it is supported
* DA is simd_abi::scalar if N==1, otherwise it is implementation-defined

Member types

Name Definition
type an ABI tag type suitable for specified element type T and size N

Helper types

template < class T, std::size_t N, class ...Abis > (parallelism TS v2)
using deduce_t = typename deduce<T, N, Abis...>::type;

Notes

simd_abi::deduce is SFINAE-friendly.

The ABI tag deduced via this facility is a Quality-of-Implementation feature. A
simple implementation might simply return fixed_size<N> unconditionally. An
optimized implementation might return an implementation-defined extended ABI tag for
most inputs. Consequently, if you need an ABI tag for a certain number of elements,
use fixed_size if ABI stability is of concern, and prefer deduce_t otherwise.

Example