std::span<T,Extent>::front
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
#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
|
(C++20)
|
access the last element (public member function) |
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