auto item = val1 + val2; // 由val1和val2相加的結(jié)果推斷出item的類型
auto i=0, *p = &i; // i是整數(shù)，p是整型指針

auto sz = 0, pi = 3.14; // Error!

int count = 10;
int& countRef = count;
auto myAuto = countRef;

countRef = 11;
cout << count << " "; // print 11

myAuto = 12;
cout << count << endl; // print 11

int i = 0;
const int ci = i, &cr = ci;
auto b = ci; // b 是一個(gè)整數(shù)（ci的頂層const特性被忽略掉）
auto c = cr; // c 是一個(gè)整數(shù)（cr是ci的別名，ci本身是一個(gè)頂層const）
auto d = &i; // d 是一個(gè)整型指針（整數(shù)的地址就是指向整數(shù)的指針）
auto e = &ci; // e 是一個(gè)指向整數(shù)常量的指針（對(duì)常量對(duì)象取地址是一種底層const）

const auto f = ci; // ci 的推演類型是int，f是const int類型

auto &g = ci; // g是一個(gè)整型常量引用，綁定到ci
auto &h = 42; // Error: 不能為非常量引用綁定字面值
const auto &j = 42; // OK: 可以為常量引用綁定字面值

auto k = ci, &l = i; // k是整數(shù)，l是整型引用
auto &m = ci, *p = &ci; // m是對(duì)整型常量的引用，p是指向整型常量的指針
auto &n = i, *p2 = &ci; // Error: i的類型是int，而&ci的類型是const int

int j = 0; // Variable j is explicitly type int.
auto k = 0; // Variable k is implicitly type int because 0 is an integer.

map<int,list<string>>::iterator i = m.begin(); 
auto i = m.begin(); 

#include <deque>
using namespace std;

int main()
{
  deque<double> dqDoubleData(10, 0.1);

  for (auto iter = dqDoubleData.begin(); iter != dqDoubleData.end(); ++iter)
  { /* ... */ }

  // prefer range-for loops with the following information in mind
  // (this applies to any range-for with auto, not just deque)

  for (auto elem : dqDoubleData) // COPIES elements, not much better than the previous examples
  { /* ... */ }

  for (auto& elem : dqDoubleData) // observes and/or modifies elements IN-PLACE
  { /* ... */ }

  for (const auto& elem : dqDoubleData) // observes elements IN-PLACE
  { /* ... */ }
}

double x = 12.34;
auto *y = new auto(x), **z = new auto(&x);

auto x = 1, *y = &x, **z = &y; // Resolves to int.
auto a(2.01), *b (&a);     // Resolves to double.
auto c = 'a', *d(&c);     // Resolves to char.
auto m = 1, &n = m;      // Resolves to int.

int v1 = 100, v2 = 200;
auto x = v1 > v2 ? v1 : v2;

int f(int x) { return x; }
int main()
{
  auto x = f(0);
  const auto & y = f(1);
  int (*p)(int x);
  p = f;
  auto fp = p;
  //...
}