The #pragma chars directive sets the sign type of char objects to be either signed or unsigned.
In order to have effect, this pragma must appear before any source statements.
Once specified, the pragma applies to the entire file and cannot be turned off. If a source file contains any functions that you want to be compiled without #pragma chars, place these functions in a different file. If the pragma is specified more than once in the source file, the first one will take precedence.