string::copy

Copy a substring to another string.

std::size_t
copy(
    char* dest,
    std::size_t count,
    std::size_t pos = 0) const;

Copies std::min(count, size() - pos) characters starting at index pos to the string pointed to by dest.

The resulting string is not null terminated.

The number of characters copied.

Name	Description
`count`	The number of characters to copy.
`dest`	The string to copy to.
`pos`	The index to begin copying from. The default argument for this parameter is `0`.

Type	Thrown On
boost::system::system_error	`pos > max_size()`.