[C++知识库]C++/C++11枚举遍历

C++11版本

...
//.hpp
enum class Week {
	Monday,
	Tuesday,
	Wednesday,
	Thursday,
	Friday,
	Saturday,
	Sunday
};
//用数组容器包装
constexpr initializer_list<Week> Weeks = { 
	Week::Monday, 
	Week::Tuesday, 
	Week::Wednesday, 
	Week::Thursday, 
	Week::Friday, 
	Week::Saturday 
	Week::Sunday 
};
//重载<<操作符，以适配Week的打印
ostream& operator << (ostream& os, const Week week);

//.cpp
ostream& operator << (ostream& os, const Week week)
{
	os << static_cast<int>(week) ;
	return os;
}

const auto week = Week::Sunday;
//遍历1，使用for (elem : Container)语法
for (const auto& w : Weeks) {
	cout << w << endl;
	if (w == week) {
		//do something
		break;
	}
}
//遍历2，使用迭代器
for (auto it = Weeks.begin(); it != Weeks.end(); ++it) {
	cout << *it << endl;
	if (*it == week) {
		//do something
		break;
	}
}

C++98版本

//.hpp
enum class Week {
	Monday,
	Tuesday,
	Wednesday,
	Thursday,
	Friday,
	Saturday,
	Sunday
};
ostream& operator << (ostream& os, const Week week);

//.cpp
ostream& operator << (ostream& os, const Week week)
{
	os << static_cast<int>(week);
	return os;
}

const Week Weeks[] = {
	Week::Monday, 
	Week::Tuesday, 
	Week::Wednesday, 
	Week::Thursday, 
	Week::Friday, 
	Week::Saturday 
	Week::Sunday 
};

//遍历
const Week week = Week::Sunday;
const unsigned wCount = sizeof(Weeks) / sizeof(Week);
for (unsigned i = 0; i < wCount; ++i) {
	cout << Weeks[i] << endl;
	if (Weeks[i] == week) {
		//do something
		...
		break;
	}
}