Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

Change the size of the string.

void
resize(
    std::size_t count,
    char ch);

Resizes the string to contain count characters. If count > size(), copies of ch are appended. Otherwise, size() is reduced to count.

Name	Description
`count`	The size to resize the string to.
`ch`	The characters to append if the size increases.

Type	Thrown On
`std::out_of_range`	`count > max_size()`