41 lines
692 B
C++
41 lines
692 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>
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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>
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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>
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static Two test(...);
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public:
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enum {
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Yes = sizeof(IsClassT<T>::test<T>(0)) == 1
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};
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enum {
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No = !Yes
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};
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};
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struct A {
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};
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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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} |