第十九章 19.3 辨别函数类型
template<typename T>
class IsFunctionT {
private:
typedef char One;
typedef struct { char a[2]; } Two;
template<typename U> static One test(...);
template<typename U> static Two test(U (*)[1]);
public:
enum { Yes = sizeof(IsFunctionT<T>::test<T>(0)) == 1 };
enum { No = !Yes };
};
这里的代码有一处错误,导致无法编译,应该修改为
template<typename T>
class IsFunctionT {
private:
typedef char One;
typedef struct { char a[2]; } Two;
template<typename U> static One test(...);
template<typename U> static Two test(U (*)[1]);
public:
enum { Yes = sizeof(IsFunctionT<T>::test<T>(0)) == 1 };
enum { No = !Yes };
};