std::experimental:: find_first_set, std::experimental:: find_last_set
From cppreference.com
<
cpp
|
experimental
|
simd
|
Defined in header
<experimental/simd>
|
||
|
template
<
class
T,
class
Abi
>
int find_first_set ( const simd_mask < T, Abi > & k ) ; |
(1) | (parallelism TS v2) |
|
template
<
class
T,
class
Abi
>
int find_last_set ( const simd_mask < T, Abi > & k ) ; |
(2) | (parallelism TS v2) |
1)
Returns the lowest index
i
where
k
[
i
]
is
true
.
2)
Returns the greatest index
i
where
k
[
i
]
is
true
.
The behavior is undefined if any_of ( k ) is false .
Parameters
| k | - |
the
simd_mask
to apply the reduction to
|
Return value
An
int
in the range
[
0
,
simd_size_v
<
T, Abi
>
)
.
Example
Run this code
#include <cstddef> #include <experimental/simd> #include <iostream> namespace stdx = std::experimental; template<typename Abi> int find(stdx::simd_mask<Abi> const& v) { if (stdx::any_of(v)) return find_first_set(v); return -1; } int main() { stdx::simd_mask<short> a{0}; a[2] = a[a.size() - 2] = 1; for (std::size_t i = 0; i < a.size(); ++i) std::cout << a[i] << ' '; std::cout << '\n'; std::cout << "find_first_set: " << stdx::find_first_set(a) << '\n'; std::cout << "find_last_set: " << stdx::find_last_set(a) << '\n'; std::cout << "find: " << find(a) << '\n'; a[2] = 0; std::cout << "find: " << find(a) << '\n'; a[a.size() - 2] = 0; std::cout << "find: " << find(a) << '\n'; }
Possible output:
0 0 1 0 0 0 1 0 find_first_set: 2 find_last_set: 6 find: 2 find: 6 find: -1