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32 lines
834 B
C++
32 lines
834 B
C++
//
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// 3.4.cpp
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// c++1x tutorial
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//
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// created by changkun at changkun.de
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//
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// 移动语义
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#include <iostream>
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class A {
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public:
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int *pointer;
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A():pointer(new int(1)) { std::cout << "构造" << pointer << std::endl; }
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A(A& a):pointer(new int(*a.pointer)) { std::cout << "拷贝" << pointer << std::endl; } // 无意义的对象拷贝
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A(A&& a):pointer(a.pointer) { a.pointer = nullptr;std::cout << "移动" << pointer << std::endl; }
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~A(){ std::cout << "析构" << pointer << std::endl; delete pointer; }
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};
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// 防止编译器优化
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A return_rvalue(bool test) {
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A a,b;
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if(test) return a;
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else return b;
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}
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int main() {
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A obj = return_rvalue(false);
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std::cout << "obj:" << std::endl;
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std::cout << obj.pointer << std::endl;
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std::cout << *obj.pointer << std::endl;
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return 0;
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}
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