std::span<T,Extent>::back
From cppreference.com
| constexpr reference back() const; |
(since C++20) | |
Returns a reference to the last element in the span.
Calling back on an empty span results in undefined behavior.
Parameters
(none)
Return value
A reference to the back element.
Complexity
Constant.
Notes
For a span c, the expression c.back() is equivalent to *(c.end() - 1).
Example
Run this code
#include <iostream> #include <span> void print_forward(std::span<const int> const span) { for (auto n{span.size()}; n != 0; --n) std::cout << span.last(n).front() << ' '; std::cout << '\n'; } void print_backward(std::span<const int> const span) { for (auto n{span.size()}; n != 0; --n) std::cout << span.first(n).back() << ' '; std::cout << '\n'; } int main() { constexpr int numbers[]{0, 1, 2, 3, 4}; print_forward(numbers); print_backward(numbers); }
Output:
0 1 2 3 4 4 3 2 1 0
See also
| access the first element (public member function) |