38 lines
861 B
C++
38 lines
861 B
C++
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// 类模版派生普通类
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#include <iostream>
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#include <cstring>
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#include <cstdlib>
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using namespace std;
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template <typename T>
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class Shape
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{
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public:
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virtual T perimeter() = 0; // 周长
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};
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// 类模版派生类模版
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// 派生的子类模版不能使用父类模版的成员变量，因为父类模版的成员变量是在编译时期确定的，而子类模版是在运行时期确定的
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template <typename T>
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class Rectangle : public Shape<T>
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{
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private:
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T width, height;
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public:
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Rectangle(T w, T h) : width(w), height(h) {}
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virtual T perimeter() { return 2 * (width + height); } // 周长
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};
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int main()
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{
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// 必须使用 int 来指定类型
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Rectangle<int> r1(10, 20);
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cout << "r1周长: " << r1.perimeter() << endl;
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Rectangle<float> r2(10.2f, 20.2f);
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cout << "r2周长: " << r2.perimeter() << endl;
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return 0;
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}
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