table of contents
std::span::front(3) | C++ Standard Libary | std::span::front(3) |
NAME¶
std::span::front - std::span::front
Synopsis¶
constexpr reference front() const;
Returns a reference to the first element in the span.
Calling front on an empty span results in undefined behavior.
Parameters¶
(none)
Return value¶
A reference to the first element.
Complexity¶
Constant
Notes¶
For a span c, the expression c.front() is equivalent to *c.begin().
Example¶
// Run this code
#include <span>
#include <iostream>
void print(std::span<const int> const data)
{
for (auto offset{0U}; offset != data.size(); ++offset) {
std::cout << data.subspan(offset).front() << ' ';
}
std::cout << '\n';
}
int main()
{
constexpr int data[] { 0, 1, 2, 3, 4, 5, 6 };
print({data, 4});
}
Output:¶
0 1 2 3
See also¶
back access the last element
(C++20) (public member function)
2022.07.31 | http://cppreference.com |