我有以下代码(抱歉大代码块,但我不能再缩小它)
template <bool B>
struct enable_if_c {
typedef void type;
};
template <>
struct enable_if_c<false> {};
template <class Cond>
struct enable_if : public enable_if_c<Cond::value> {};
template <typename X>
struct Base { enum { value = 1 }; };
template <typename X, typename Y=Base<X>, typename Z=void>
struct Foo;
template <typename X>
struct Foo<X, Base<X>, void> { enum { value = 0 }; };
template <typename X, typename Y>
struct Foo<X, Y, typename enable_if<Y>::type > { enum { value = 1 }; …