#include <cstdint>
#include <iostream>
#include <span>

constexpr static std::int32_t a[]{1, 2, 3, 4, 5};
constexpr static std::span s{a};

static_assert
(
    sizeof(int32_t) == 4 &&
    std::size(a) == 5 &&
    sizeof a == 20 &&
    s.size() == 5 &&
    s.size_bytes() == 20
);
 
int main()
{
    // typically, a static span holds only a pointer:
    std::cout << sizeof(s) << '\n';
}