string::push

`string::push_back`

Append a character.

void
push_back(
    char ch);

Appends a character to the end of the string.

Strong guarantee.

Name	Description
`ch`	The character to append.

Type Thrown On

Type	Thrown On
`boost::system::system_error`	`size() + 1 > max_size()`.

boost::system::system_error

size() + 1 > max_size().