#include <iostream>

#include <vector>

#include <map>

#include <string>

#include <algorithm>

#include <utility>

#include <tuple>

#include <functional>

#include <memory>

using namespace std;

void F(int a){

	cout<<"int:"<<a<<endl;

}

void F(int *pa){

	cout<<"int *:"<< pa <<endl;

}

void PrintVector(const vector<int> & vi){

	cout<< "[";

	for(auto it = vi.begin(); it != vi.end(); ++it){

		cout<< *it <<",";

	}

	cout<< "]" <<endl;

}

struct Sum{

	Sum(){sum=0;}

	void operator()(int n){ sum += n; }

	int sum;

};

template<typename T>

void Print(T t){

    cout<< t <<endl;

}

template<typename Head, typename... Tail>

void Print(Head head, Tail... tail) {

    cout<< head <<", ";

    Print(tail...);

}

class Foo{

public:

	Foo(){ cout<< "Foo construct."<< this  <<endl;}

	~Foo(){ cout<< "Foo destruct."<< this <<endl; }

	int val;

	void bar(){ cout<< "Foo.bar() called."<< val <<endl; }

};

int main(){

	/****************************************/

	auto i = 12345678;

	auto s = "Hello中国";

	auto f = 3.14;

	vector<int> vi {1,2,3,4};

	decltype(f) d = 6.28;

	PrintVector(vi);

	cout<< i << endl;

	cout<< s << endl;

	cout<< f << endl;

	// old style: vector<int>::iterator it = vi.begin()

	cout<< endl;

	cout << "decltype(x):"  << d <<endl;

	/****************************************/

	// NULL vs. nullptr

	int a = 0;

	int *pa = nullptr;

	int *pb = NULL;

	F(a);

	F(pa);

	F(pb);

	bool bEqual = (pa == pb);

	cout<< bEqual <<endl;

	/****************************************/

	// for_each

	map<string,int> m1 {

			{"Hello中国",110},

			{"美国",345},

			{"Japan",000}

		};

	for(auto item: m1){

		cout<<"Key:"<<item.first<<",Value:"<<item.second<<endl;

	}

	for_each(vi.begin(),vi.end(),[](int & x){ x*=2; } );

	PrintVector(vi);

 	// Calls Sum::operator() for each number

	Sum sum1 = for_each(vi.begin(),vi.end(),Sum());

	cout<<"Sum:"<<sum1.sum<<endl;

	int arg1=1,arg2=2;

	for_each(vi.begin(),vi.end(),[=](int & x){ x *=(arg1+arg2); } );

	PrintVector(vi);

	for_each(vi.begin(),vi.end(),[=](int & x) -> int { return  x *(arg1+arg2); } );

	PrintVector(vi);

	/****************************************/

	// 变长参数模板

	auto pair1 = make_pair(110,"Hello中国");

	cout<< "pair.first:"<<pair1.first<<",pair.second:"<<pair1.second<<endl;

	auto tuple1 = make_tuple("Hello",1,3.14);

	cout<< std::get<0>(tuple1) <<endl;

	cout<< std::get<1>(tuple1) <<endl;

	cout<< std::get<2>(tuple1) <<endl;

	Print(1);

	Print(1,"Hello中国");

	Print(1,"Hello中国",3.1415926);

	cout<< "******************************" <<endl;

	// unique_ptr具有转移语义

	unique_ptr<Foo> p1(new Foo());

	if(p1) p1->val = 123;

	if(p1) p1->bar();

	{

		unique_ptr<Foo> p2 = std::move(p1);

		p2->val *=2;

		p2->bar();

	}

	if(p1) p1->bar();

	cout<< "******************************" <<endl;

	// shared_ptr

	shared_ptr<Foo> sp1(new Foo());

	if(sp1) sp1->val = 123;

	if(sp1) sp1->bar();

	{

		shared_ptr<Foo> sp2 = sp1;

		sp2->val *=2;

		sp2->bar();

	}

	if(sp1) sp1->bar();

	return 0;

}