测试“形参为对象时的默认参数”

test_constructor.cpp

#include <iostream>

class Foo {
public:
    Foo() : a(0) {}
public:
    int a;
};

void myprint(const Foo& foo = Foo()) {
    std::cout << foo.a << std::endl;
}

int main() {
    Foo foo;
    foo.a = 2;
    myprint();
    return 0;
}