vector::operator[]
Visual Studio 2010
Returns a reference to the vector element at a specified position.
reference operator[]( size_type _Pos ); const_reference operator[]( size_type_Pos ) const;
If the return value of operator[] is assigned to a const_reference, the vector object cannot be modified. If the return value of operator[] is assigned to a reference, the vector object can be modified.
When compiling with _SECURE_SCL 1, a runtime error will occur if you attempt to access an element outside the bounds of the vector. See Checked Iterators for more information.