Template class partial specialisation problem

From: Lionel B (google_at_lionelb.com)
Date: 11/03/04 

Date: 3 Nov 2004 06:44:28 -0800

Greetings.

The following code compiles ok and does what I'd expect it to do:

[apologies for the lack of indentation... Google Groups 2 Beta bug
reported]

---------- START CODE ----------

// test.cpp

#include <iostream>

template <class T> struct A
{
A();
};

A<int>::A()
{
std::cout << "Template parameter is \"int\"" << '\n';
}

A<long>::A()
{
std::cout << "Template parameter is \"long\"" << '\n';
}

int main()
{
A<int> a1;
A<long> a2;

return 0;
}

---------- END CODE ----------

The program outputs:

Template parameter is "int"
Template parameter is "long"

So far so good... now I would like to do the same, but there is a
second template parameter and I only want to specialise on the first:

---------- START CODE ----------

// test.cpp

#include <iostream>

template <class T, class R> struct A
{
A();
};

template <class R> A<int, R>::A() // line 10
{
std::cout << "First template parameter is \"int\"" << '\n';
}

template <class R> A<long, R>::A() // line 15
{
std::cout << "First template parameter is \"long\"" << '\n';
}

int main()
{
A<int, int> a1;
A<long, int> a2;

return 0;
}

---------- END CODE ----------

My compiler (gcc 3.3.3 cygwin special) throws this out with:

g++ test.cpp -o test.exe
test.cpp:10: error: parse error before `)' token
test.cpp:15: error: parse error before `)' token

I can't figure out quite what the syntax should be to specialise on the
first template parameter only. It would seem that A<int, R>::A() is
still a template function, but my compiler doesn't like the "obvious"
definition:
template <class R> A<int, R>::A()

Any help appreciated, 

-- 
Lionel B

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