33 lines
634 B
C++
33 lines
634 B
C++
//
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// Created by light on 20-1-5.
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//
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#include <iostream>
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using namespace std;
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template <typename T> class IsClassT {
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private:
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typedef char One;
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typedef struct {
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char a[2];
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} Two;
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template <typename C> static One test(int C::*);
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// Will be chosen if T is anything except a class.
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template <typename C> static Two test(...);
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public:
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enum { Yes = sizeof(IsClassT<T>::test<T>(0)) == 1 };
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enum { No = !Yes };
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};
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struct A {};
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int main() {
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// 0不能转换为int int::*因为int不是类，所以它不能有成员指针。
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cout << IsClassT<int>::Yes << endl;
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cout << IsClassT<A>::Yes << endl;
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return 0;
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} |