Fix bug on initializing class member reference

[ericzeng95]

CPlusPlusThings/codingStyleIdioms/1_classInitializers/1.3_const.cpp

Lines 6 to 21 in c9d0f14

	#include <iostream>
	class Animal {
	public:
	Animal(int age,std::string name):age_(age),name_(name) {
	std::cout << "Animal(int age) is called" << std::endl;
	}
	private:
	int &age_;
	const std::string name_;
	};
	int main() {
	Animal animal(10,"hh");
	return 0;
	}

The original code is wrong. Here class memebr reference variable age_ is binding to constructor parameter age, which is passed by value. When the constructor finishes, this variable goes out of scope, and the binded refernce age_ is dangling. All subsequent usage of age_ is undefined behaviour

[FlyDragonMan]

I have already received the letter you sent me. I will reply and deal with it as soon as possible.ChenMingMing