std::span<T,Extent>::back
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
#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) |
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