typedef struct _D3DMATRIX {union {struct {float _11, _12, _13, _14;float _21, _22, _23, _24;float _31, _32, _33, _34;float _41, _42, _43, _44;};float m[4][4];};} D3DMATRIX; 如图中所示,为什么这个类中的union需要一个struct(4*4的),还需要一个floatm[4][4]呢?这两个不是重复么?
typedef struct _D3DMATRIX {union {struct {float _11, _12, _13, _14;float _21, _22, _23, _24;float _31, _32, _33, _34;float _41, _42, _43, _44;};float m[4][4];};} D3DMATRIX;