结构体内重载operator =；结构体重载输出运算符＜＜

结构体内重载operator =；结构体重载输出运算符＜＜"/>

结构体内重载operator =；结构体重载输出运算符＜＜

• 结构体内重载operator =；结构体内声明，结构体外定义；注意operator 是结构体的operator
• 结构体重载输出运算符<< ；注意 operator 是全局的operator

#include <iostream>class B {
public:B(int data) : _data(data) {}B& operator = (const B& _b) {this->_data = _b._data;return *this;}friend std::ostream& operator << (std::ostream& out, B& _B) { out << _B._data; return out; }
private:int _data;
};struct A {A(int _a, double _d, B _b) : a(_a), d(_d), b(_b) {}int a;double d;B b;A& operator = (const A& _a);friend std::ostream& operator << (std::ostream& out, A& _A);
};A& A::operator = (const A& _a) {this->a = _a.a;this->d = _a.d;this->b = _a.b;return *this;
}std::ostream& operator << (std::ostream& out, A& _A) {out << "a = " << _A.a <<std::endl;out << "d = " << _A.d <<std::endl;out << "b = " << _A.b <<std::endl;return out;
}int main() {std::cout << "test begin! " << std::endl;A a(2, 8.99, B(3));std::cout << a;std::cout << "---- " << std::endl;A b(2222, 3338.99, B(43));std::cout << b;std::cout << "---- " << std::endl;b = a;std::cout << b;std::cout << "---- " << std::endl;return 0;
}