相关疑难解决方法(0)

我可以用c ++/g ++做到这一点:

struct vec3 { 
    union {
        struct {
            float x, y, z;
        }; 
        float xyz[3];
    }; 
};

然后,

vec3 v;
assert(&v.xyz[0] == &v.x);
assert(&v.xyz[1] == &v.y);
assert(&v.xyz[2] == &v.z);

将工作.

如何使用gcc在c中执行此操作？我有

typedef struct {
    union {
        struct {
            float x, y, z;
        };
        float xyz[3];
    };
} Vector3;

但我特别是周围都有错误

line 5: warning: declaration does not declare anything
line 7: warning: declaration does not declare anything