std::span<T,Extent>::back
From cppreference.com
| constexpr reference back() const; |
||
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 <span> #include <iostream> 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
| (C++20) |
access the first element (public member function) |