#include <iostream>
#include <typeinfo>
using namespace Std;
Template <class t>
T Add (t one, T)
{
cout << "type:" << typeid (T). Name () << Endl;
return one + one; Function templates are compiled only when they are called, and some compilers compile at first compile time
}
int add (int one, int)
{
cout << "Custom int" << Endl;
return one + one;
}
Template <class T, class f>//function templates can not only accept data types, but also accept operation types
void Show (T T, F F)
{
F (t);
}
void Show_ (int temp)
{
cout << temp << Endl;
}
Template<class T1, Class t2>
Auto Temp1 (T1 t1, T2 T2)->decltype (T1+T2)//automatic type inference
{
return t1 + T2;
}
Template<class t>
void Temp2 (T t)
{
Decltype (t) D; Create a variable of the same type as T
}
int main ()
{
cout << Add (1.2, 1.2) << Endl;
cout << Add (1, 2) << Endl; If there is a custom function int add (int, int), the custom will be preferred, otherwise the function template will be used
cout << add<int> << Endl; If a function template is instantiated, the function template is used regardless of whether or not the custom function add
Show (1, Show_);
Show (1, [] (int i) {cout << i << "lambda" << Endl;}); You can pass a lambda expression as an action type to a function template
int a = 10;
Decltype (a) b = 3; The function of the decltype is to copy the data type
cout << Temp (1.2, 1) << Endl;
cout << Temp (1, 1.2) << Endl;
return 0;
}
C + + function template review
