NAME¶

std::span::size - std::span::size

Synopsis¶

constexpr size_type size() const noexcept; (since C++20)

Returns the number of elements in the span.

Parameters¶

(none)

Return value¶

The number of elements in the span.

Note¶

Feature-test macro Value Std Feature
__cpp_lib_ssize 201902L (C++20) std::ssize and unsigned std::span::size

Example¶

// Run this code

#include <iostream>
#include <span>

void show_sizes(std::span<const int> span)
{
std::cout
<< span .size() << ' ' // 8
<< span.first(7) .size() << ' ' // 7
<< span.first<6>() .size() << ' ' // 6
<< span.last(5) .size() << ' ' // 5
<< span.last<4>() .size() << ' ' // 4
<< span.subspan(2, 3) .size() << ' ' // 3
<< span.subspan<3, 2>() .size() << ' ' // 2
<< '\n';
}

int main()
{
int antique_array[]{1, 2, 3, 4, 5, 6, 7, 8};
show_sizes(antique_array);
}

Output:¶

8 7 6 5 4 3 2

See also¶

constructor constructs a span
(public member function)
size_bytes returns the size of the sequence in bytes
(public member function)