url_base::reserve

Adjust the capacity without changing the size.

void
reserve(
    std::size_t n);

This function adjusts the capacity of the container in characters, without affecting the current contents. Has no effect if n <= this->capacity().

Strong guarantee. Calls to allocate may throw.

Type	Thrown On
`bad_alloc`	Allocation failure

Name	Description
`n`	The capacity in characters, excluding any null terminator.