Definition: Write a program to process different tasks

Function Template

template <template T>
inline const T& larger(const T& a, const T& b)
{return (a < b)? b : a;}

The program will generate functions and classes during compilation time

It will generate new functions and classes when encountering new types of variables

This is called template instantiation, T is the formal parameter

template <class T>

This is the same as typename

larger(2,4) //inplicit
larger<int>(2,4) //expilicit

larger(2,2.2) //Error!
larger<double>(2,2.2)

Type conversion for templates

const char* m = "Haha"
const char* a = "GG"

larger(a,m)

This will compare the address of the two objects(The time of creation)

template <template T>
bool equal(T& a,T&b)
{
	return a == b;
}

template <>
bool float(T& a,T&b)
{
	return (a - b) < 1;
}

To create Exceptional case to process types that general version cannot process

When there are too many combinations of arguments, it is not wise to use template because you need to implement so many functions

template <typename T1, typename T2>inline const T1&
	larger(const T1& a, const T2& b)return (a < b)? a : b;

This will create temporary value to compare a and b(only the same type can compare)

And then create another temporary value to return

In this case, since it is return by reference, returning a temporary object will cause trouble