Question

I have the following code

//Point.h #define WIDTH 8 #define HEIGHT 8  typedef struct Point {   char x;   char y; } Point;  //Board.c #include <stdbool.h>  // Some other functions that we don't care about...   bool inBounds(Point * p) {   return p->x >= 0     && p->x <= WIDTH     && p->y >= 0     && p->y <= HEIGHT; } 

When I compile this (ppu-gcc 4.1.1), I get the following warning

warning: comparison is always true due to limited range of data type 

even though the range of char is -127 to 127 and WIDTH is 8, which is well inside the range of a char. I’ve already tried an explicit cast of WIDTH to a char, but still got the error.

Answer 1

Are you sure that char is signed? Try declaring the fields explictly as signed char and see what you get.