Usage notes
- If the two buffer pointers are the same, the trimming is done in place.
If they are not the same, the blank-padded string is copied into the null-terminated
string buffer. After copying, the buffer is scanned backwards from the end
until a nonspace character is found. The byte following the nonspace character
is then overwritten with a null character.
- If String and Buffer partially
overlap, the result is undefined.