object::operator[]
Access or insert the specified element.
Synopsis
value&
operator[](
string_view key);
Description
Returns a reference to the value that is mapped to a key equivalent to key, performing an insertion of a null value if such key does not already exist.
If an insertion occurs and results in a rehashing of the container, all iterators including any past-the-end iterators, and all references to the elements are invalidated. Otherwise, no iterators or references are invalidated.
Complexity
Constant on average, worst case linear in size()
.
Exception Safety
Strong guarantee. Calls to memory_resource::allocate
may throw.
Return Value
A reference to the mapped value.
Parameters
Name | Description |
---|---|
|
The key of the element to find. |