"由于C中数据类型的警告范围有限,比较总是如此？

Question

我有以下代码

//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;
}

当我编译它(ppu-gcc 4.1.1)时,我收到以下警告

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

即使char的范围是-127到127并且WIDTH是8,这完全在char的范围内.我已经尝试过对一个char进行WIDTH的显式转换,但仍然遇到了错误.

Answer 1

你确定char签了吗？尝试明确地声明字段signed char,看看你得到了什么.