insert_len

Adds a copy of the first len bytes of string to the StringChunk.

The copy is nul-terminated.

Since this function does not stop at nul bytes, it is the caller's responsibility to ensure that string has at least len addressable bytes.

The characters in the returned string can be changed, if necessary, though you should not change anything after the end of the string.

Parameters:

this	a StringChunk
len	number of bytes of string to insert, or -1 to insert a nul-terminated string
string	bytes to insert

Returns:

a pointer to the copy of string within the StringChunk