Could anyone tell me about template partial specialization..?

[BekTek]

I'm still confused about the template partial specialization which is used
in many libraries..
due to lack of introduction for beginner..

Could you tell me about that in short?
Thanks in advance..

 

[Sharad Kala]

I'm still confused about the template partial specialization which is used
in many libraries..
due to lack of introduction for beginner..

Consider this code -

#include <iostream>
using namespace std;

template<class T1, class T2>
struct A
{
void foo()
{
cout << "Primary template\n";
}
};

template<class T1>
struct A<T1, int>
{
void foo()
{
cout << "Partial specialization\n";
}
};

int main()
{
A<float, double> a1;
a1.foo(); // Calls primary template

A<float, int> a2;
a2.foo(); // Calls partial specialization
}

Analyze the code, whenever the second template parameter is an int the
partial specialization gets chosen.

Sharad