at() [1/2]

const ElementType& at ( std::size_t  off ) const

noexcept

A functional read-only accessor of a vector element by its index.

Parameters

off	The index of the accessed element in the vector.

Returns

A read-only reference to the accessed element.

The function does not verify the validity of the index: if one addresses an element out of the valid range, the behavior is undefined.