std::experimental::simd_cast, std::experimental::static_simd_cast

 

C++

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Experimental

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Library fundamentals 3 (library fundamentals TS v3)

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Extensions for concurrency 2 (concurrency TS v2)

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Extensions for parallelism v2

Parallel exceptions
exception_list
Additional execution policies
execution::vector_policy	execution::unsequenced_policy
Algorithms
induction reductionreduction_plusreduction_minusreduction_multiplies	reduction_bit_andreduction_bit_orreduction_bit_xorreduction_minreduction_max	for_loopfor_loop_stridedfor_loop_nfor_loop_n_strided
execution::no_vec
execution::ordered_update_t
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SIMD library

Main classes
simd	simd_mask
ABI tags
simd_abi::scalar simd_abi::fixed_size	simd_abi::native simd_abi::compatible	simd_abi::max_fixed_size simd_abi::deduce
Alignment tags
element_aligned_tagelement_aligned	vector_aligned_tagvector_aligned	overaligned_tagoveraligned
Where expression
where	where_expression	const_where_expression
Casts
simd_caststatic_simd_cast	to_fixed_sizeto_compatibleto_native	splitsplit_by concat
Algorithms
min max	minmax clamp
Reduction
reducehminhmax
Mask reduction
all_ofany_ofnone_ofsome_of	popcount find_first_setfind_last_set
Traits
is_simdis_simd_mask is_abi_tag is_simd_flag_type	simd_size memory_alignment rebind_simdresize_simd
Math functions

 

Defined in header <experimental/simd>
template< class V, class T, class Abi > /*see below*/ simd_cast( const simd<T, Abi>& v ) noexcept;	(1)	(parallelism TS v2)
template< class V, class T, class Abi > /*see below*/ static_simd_cast( const simd<T, Abi>& v ) noexcept;	(2)	(parallelism TS v2)

Cast a simd object to another simd object. If V is T, returns simd<T, Abi>; otherwise, if V is a scalar type, returns simd<V, simd_abi::fixed_size<simd<T, Abi>::size()>>. Otherwise, V must be a simd type, and the function returns V.

1) This function does not participate in overloading resolution unless

• every possible value of the input element can be represented with the output element,
• either is_simd_v<V> is false, or V::size() is simd<T, Abi>::size().

2) This function does not participate in overloading resolution unless either is_simd_v<V> is false, or V::size() is simd<T, Abi>::size().

Parameters

v

-

the input simd object

Return value

A simd object with the i-th element initialized to static_cast<To>(v[i]), where To is the output element type as specified.

Notes

The TS specification is missing simd_cast and static_simd_cast overloads for simd_mask. The libstdc++ implementation provides the missing overloads in the std::experimental::__proposed namespace. If you already use the

namespace stdx = std::experimental;

shortcut, you might be interested to use

namespace stdx {
  using namespace std::experimental;
  using namespace std::experimental::__proposed;
}

instead. Alternatively, libstdc++ implements a __cvt() member function in simd_mask, which allows implicit conversion of the mask. See also: https://.com/VcDevel/std-simd/issues/41