initializer_list

1 构造函数场景

class P {
public:P(int a, int b) {std::cout << "int, int" << std::endl;}P(std::initializer_list<int> initList) {std::cout << "initializer_list" << std::endl;}
};

调用：

P p(1, 2);
P q{1, 2};
P r{1, 2, 4};
P s = {1, 2};

int, int
initializer_list
initializer_list
initializer_list

2 算法场景

min({1, 2, 3});
max({1, 2, 3});

源码

  // N2722 + DR 915.template<typename _Tp>_GLIBCXX14_CONSTEXPRinline _Tpmin(initializer_list<_Tp> __l){ return *std::min_element(__l.begin(), __l.end()); }template<typename _Tp, typename _Compare>_GLIBCXX14_CONSTEXPRinline _Tpmin(initializer_list<_Tp> __l, _Compare __comp){ return *std::min_element(__l.begin(), __l.end(), __comp); }template<typename _Tp>_GLIBCXX14_CONSTEXPRinline _Tpmax(initializer_list<_Tp> __l){ return *std::max_element(__l.begin(), __l.end()); }template<typename _Tp, typename _Compare>_GLIBCXX14_CONSTEXPRinline _Tpmax(initializer_list<_Tp> __l, _Compare __comp){ return *std::max_element(__l.begin(), __l.end(), __comp); }