string::insert (2 of 4 overloads)

Insert a character.

string&
insert(
    std::size_t pos,
    std::size_t count,
    char ch);

Inserts count copies of ch at the position pos.

Strong guarantee.

All references, pointers, or iterators referring to contained elements are invalidated. Any past-the-end iterators are also invalidated.

*this

Name	Description
`pos`	The index to insert at.
`count`	The number of characters to insert.
`ch`	The character to insert.

Type	Thrown On
`system_error`	`size() + count > max_size()`
`system_error`	`pos > size()`