std::inplace_vector<T,N>:: operator[]

Returns a reference to the element at specified location pos .

If pos < size ( ) is false :

• If the implementation is hardened , a contract violation occurs. Moreover, if the contract-violation handler returns under “observe” evaluation semantic, the behavior is undefined.
• If the implementation is not hardened, the behavior is undefined.

Parameters

Return value

Reference to the requested element.

Complexity

Constant.

Notes

Unlike std::map::operator[] , this operator never inserts a new element into the container. Accessing a nonexistent element through this operator is undefined behavior, unless the implementation is hardened.

Example

#include <inplace_vector>
#include <iostream>
int main()
{
    std::inplace_vector<int, 4> numbers{2, 4, 6, 8};
    std::cout << "Second element: " << numbers[1] << '\n';
    numbers[0] = 5;
    std::cout << "All numbers:";
    for (auto i : numbers)
        std::cout << ' ' << i;
    std::cout << '\n';
}

Second element: 4
All numbers: 5 4 6 8

See also