c++ auto / decltype / std::typeid

通用传入接口 auto

int a = 1;

double b = 1.111;

auto at = a ;  //at =int 

auto at1= b ;// at1 = double

通用备份接口 decltype 

int a = 1;

double b = 1.111;

decltype(a) dt ;  //dt = int;

decltype(db) dt 1; //dt1 = double 

获取变量数据类型 

int a ;

std::cout<<std::typeid(a).name() <<std::endl;   == std::cout<<"int " ;