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std::span::operator[](3) | C++ Standard Libary | std::span::operator[](3) |
NAME¶
std::span::operator[] - std::span::operator[]
Synopsis¶
constexpr reference operator[](size_type idx) const;
Returns a reference to the idx-th element of the sequence. The behavior is
undefined
if idx is out of range (i.e., if it is greater than or equal to size()).
Parameters¶
idx - the index of the element to access
Return value¶
A reference to the idx-th element of the sequence, i.e., data()[idx]
Exceptions¶
Throws nothing.
Example¶
// Run this code
#include <iostream>
#include <span>
#include <utility>
void reverse(std::span<int> span) {
for (std::size_t i = 0, j = std::size(span); i < j; ++i) {
--j;
std::swap(span[i], span[j]);
}
}
void print(std::span<const int> const span) {
for (int element: span) {
std::cout << element << ' ';
}
std::cout << '\n';
}
int main() {
int data[]{ 1, 2, 3, 4, 5 };
print(data);
reverse(data);
print(data);
}
Output:¶
1 2 3 4 5
5 4 3 2 1
See also¶
data returns a pointer to the beginning of the sequence of
elements
(public member function)
size returns the number of elements in the sequence
(public member function)
2022.07.31 | http://cppreference.com |