# std::experimental::simd_mask<T,Abi>::simd_mask

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< cpp‎ | experimental‎ | simd‎ | simd mask

simd_mask() noexcept = default; | (1) | (parallelism TS v2)
explicit simd_mask( bool value ) noexcept; | (2) | (parallelism TS v2)
template< class U > simd_mask( const simd_mask<U, simd_abi::fixed_size<size()>>& other ) noexcept; | (3) | (parallelism TS v2)
template< class U, class Flags > simd_mask( const bool* mem, Flags flags ); | (4) | (parallelism TS v2)
simd_mask( const simd_mask& other ) noexcept = default; | (5) | (parallelism TS v2) (implicitly declared)
simd_mask( simd_mask&& other ) noexcept = default; | (6) | (parallelism TS v2) (implicitly declared)

1) Constructs a `simd_mask` using default initialization (constructed without initializer) or value initialization (constructed with an empty initializer).
2) The broadcast constructor constructs a `simd_mask` with all values initialized to value.
3) Constructs a `simd_mask` where the i-th element is initialized to other[i] for all i in the range of `[`​0​`,` `size()``)`. This overload participates in overload resolution only if `Abi` is simd_abi::fixed_size<size()>.
4) The load constructor constructs a `simd_mask` where the i-th element is initialized to mem[i] for all i in the range of `[`​0​`,` `size()``)`.
5-6) Implicitly declared copy and move constructors. Constructs a `simd_mask` where each element is initialized from the values of the elements in other.

### Parameters

value | - | the value used for initialization of all `simd_mask` elements
other | - | another `simd_mask` to copy from
mem | - | a pointer into an array where `[`mem`,` mem + size()`)` is a valid range
flags | - | if of type `vector_aligned_tag`, the load constructor may assume `mem` to point to storage aligned by `memory_alignment_v<simd_mask>`
Type requirements
- `is_simd_flag_type_v<Flags>` must be true.

### Example

Run this code

    #include <algorithm>
    #include <experimental/simd>
    #include <iostream>
    namespace stdx = std::experimental;

    int main()
    {
        [[maybe_unused]]
        stdx::native_simd_mask<int> a;       // uninitialized
        stdx::native_simd_mask<int> b(true); // all elements initialized with true
        stdx::native_simd_mask<int> c{};     // all elements initialized with false

        alignas(stdx::memory_alignment_v<stdx::native_simd_mask<int>>)
            std::array<bool, stdx::native_simd_mask<int>::size() * 2> mem = {};
        std::ranges::generate(mem, [i{0}] mutable -> bool { return i++ & 1; });

        stdx::native_simd_mask<int> d(&mem[0], stdx::vector_aligned);  // {0, 1, 0, 1, ...}
        stdx::native_simd_mask<int> e(&mem[1], stdx::element_aligned); // {1, 0, 1, 0, ...}

        const auto xored = b ^ c ^ d ^ e;

        for (std::size_t i{}; i != xored.size(); ++i)
            std::cout << xored[i] << ' ';
        std::cout << '\n';
    }

Possible output:

    0 0 0 0 0 0 0 0

### See also

element_aligned_tag element_aligned (parallelism TS v2) | flag indicating alignment of the load/store address to element alignment (class)
vector_aligned_tag vector_aligned (parallelism TS v2) | flag indicating alignment of the load/store address to vector alignment (class)
overaligned_tag overaligned (parallelism TS v2) | flag indicating alignment of the load/store address to the specified alignment (class template)
memory_alignment (parallelism TS v2) | obtains an appropriate alignment for `vector_aligned` (class template)
copy_from (parallelism TS v2) | loads `simd_mask` elements from contiguous memory (public member function)

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