C++11新特性

1.auto

auto maton=112;                      //maton is type int

auto pt=&maton                        //pt is type int*

typedef double (*Fp)(double,int);

Fb fm=0;

auto pf=fm;                              //pf is type double(*)(double ,int)

2.decltype

double x(0);

int n(0);

decltype (x*n) q=0;        //q is same type as x*n,i.e.,double

decltype (&x)pd=&x;      //pd same type as &x,double*

int &i=n;

const int& ic=n;           

decltype(i) i1=n;            
  //i1 same type as int&

decltype(ic) i2=n;             //i2 same type as const int&

3 using=

typedef std::vector<double>::iterator itTyped1;

using itTyped2=std::vector<double>::iterator;

itTyped1 it1;

itTyped it2;