std::full_extent, std::full_extent_t
From cppreference.com
| Defined in header <mdspan>
|
||
struct full_extent_t { explicit full_extent_t() = default; }; |
(1) | (since C++26) |
inline constexpr std::full_extent_t full_extent {}; |
(2) | (since C++26) |
1) The class
std::full_extent_t is a slice specifier type that can be used in std::submdspan.2) The corresponding
std::full_extent instance of (1) is a slice specifier to indicate full range of indices in the specified extent in std::submdspan.Example
Run this code
#include <mdspan>
#include <print>
void print(auto view)
{
static_assert(view.rank() <= 2);
if constexpr (view.rank() == 2)
{
for (std::size_t i = 0; i != view.extent(0); ++i)
{
for (std::size_t j = 0; j != view.extent(1); ++j)
std::print("{} ", view[i, j]);
std::println();
}
}
else if constexpr (view.rank() == 1)
{
for (std::size_t i = 0; i != view.extent(0); ++i)
std::print("{} ", view[i]);
std::println();
}
else
std::println("{}", view[]);
std::println();
}
int main()
{
const char letters []{'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I'};
const std::mdspan view(letters, 3, 3);
print(view);
print(std::submdspan(view, std::full_extent, std::full_extent));
print(std::submdspan(view, std::full_extent, 1));
print(std::submdspan(view, 1, std::full_extent));
print(std::submdspan(view, 2, 1));
}
Possible output:
A B C
D E F
G H I
A B C
D E F
G H I
B E H
D E F
H
See also
(C++26) |
returns a view of a subset of an existing mdspan (function template) |