Structure template c++

[knightrider007]

What is the difference between

template<typename T>
struct arg_type {
typedef T* ptr;
typedef T& ref;

static T& myFun(T& a) {return a;}
}

template<typename T>
struct arg_type<T*> {
typedef T* ptr;
typedef T& ref;

static T& myFun(T* a) {return *a;}
}

template<typename T>
struct arg_type<T&> {
typedef T* ptr;
typedef T& ref;

static T& myFun(T& a) {return &a;}


The thing which confuses me the most is template part following the struct keyword
}

[vlad from moscow]

From the C++ Standard

1 A primary class template declaration is one in which the class template name is an identifier. A template declaration in which the class template name is a simple-template-id is a partial specialization of the class template named in the simple-template-id. A partial specialization of a class template provides an alternative definition of the template that is used instead of the primary definition when the arguments in a specialization match those given in the partial specialization

[knightrider007]

@Vlad

Thank you very much for the reply.

Could you please give a pointer to some website or article explaining this..... with examples if possible

[vlad from moscow]

I even do not know such references. Try to find them yourself by using keyword "Class template partial specializations"

[JLBorges]

http://www.informit.com/guides/content.aspx?g=cplusplus&seqNum=50
http://publib.boulder.ibm.com/infocenter/lnxpcomp/v8v101/topic/com.ibm.xlcpp8l.doc/language/ref/partial_specialization.htm
http://www.parashift.com/c++-faq/template-specialization-example.html

[knightrider007]

@Vlad Rhank you for the keyword

@JLBorges Thank you very much for providing the reference