C++11——1.小练手

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#include <iostream>#include <vector>#include <map>#include <string>#include <algorithm>#include <tuple>using namespace std;// nullptrvoid F(int a) {cout << "F(int a):" << a << endl;}void F(int *p) {cout << "F(int *p):" << p << endl;}void main() {// autocout << "auto---------------------\n";{auto a = "test auto\n";cout << a;vector<int>v;v.push_back(0);v.push_back(1);v.push_back(2);for (auto itr = v.begin(); itr != v.end(); ++itr) {cout << *itr << endl;}// template <class Product, class Creator>// void processProduct(const Creator &creator) {// Product *val = creator.makeObject();// }// // template <class Creator>// void processProduct(const Creator &creator) {// auto val = creator.makeObject();// }}// decltypecout << "decltype---------------------\n";{int x = 3;decltype(x) y = 3;// template <class Creator>// auto processProduct(const Creator &creator) -> decltype(creator.makeObject()) {// auto val = creator.makeObject();// }}// nullptrcout << "nullptr---------------------\n";{int *p = nullptr;int *q = NULL;cout << "p equals q: " << (p == q) << endl;//int a = nullptr;// errorF(0);F(nullptr);}// forcout << "for---------------------\n";{//map<string, int> m {{"a", 1}, {"b", 2}, {"c", 3}};map<string, int> m; m["a"] = 1; m["b"] = 2; m["c"] = 3;for (auto p : m) {cout << p.first << ":" << p.second << endl;}}// lambda// [Func Object Param](Func Param)->ReturnType {Func Body}cout << "lambda---------------------\n";{//vector<int> v {5, 4, 3, 2, 1};vector<int> v; v.push_back(5); v.push_back(4); v.push_back(3); v.push_back(2); v.push_back(1);int a = 2, b = 1;// can visit global var 'b'for_each(v.begin(), v.end(), [b](int &x){ cout << (x + b) << endl;});// [=] means can visit all outer var (by value)for_each(v.begin(), v.end(), [=](int &x){ x *= (a + b);});for_each(v.begin(), v.end(), [=](int &x)->int{ return x * (a + b);});}// var params length templatecout << "var param len template---------------------\n";{auto t1 = make_tuple(1, 2.0, "c++ 11");//auto t2 = make_tuple(1, 2.0, "c++ 11", {1, 0, 2});// template <typename head, typename... tail>// void Print(Head head, typename... tail) {// cout << head << endl;// Print(tail...);// }}// init methodcout << "init method---------------------\n";{int arr[3] = {1, 2, 3};vector<int> v(arr, arr + 3);// int arr1[3] {1, 2, 3};// vector<int> v1 {1, 2, 3};// map<int, string> {{1, "a"}, {2, "b"}};// string str{"Hello World"};}getchar();}
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