Template function calling a templated function in the templated class

[Charles Karney]

Configuration:
  g++ (GCC) 4.0.2 20051125 (Red Hat 4.0.2-8)
  Fedora Core 4, 2.6.16, i686

Consider the following code

  #include <iostream>
  #include <limits>

  class foo {
  public:
    template<class S> int foof0()
      { return std::numeric_limits<S>::digits; }
    template<class S> int foof1(S a)
      { return std::numeric_limits<S>::digits; }
  };

  class bar {
  public:
    template<class X> int barf(X x) { return x.foof0<double>(); }
    // template<class X> int barf(X x) { return x.foof1(1.0); }
  };

  int main() {
    foo a;
    bar b;
    std::cout << b.barf(a) << std::endl;
  }

bar::barf is templated on the type of its argument and, with an argument
of type foo, is supposed to call foo::foof0<double>().  Compiling this
with g++ gives:

  g++     test.cpp   -o test
  test.cpp: In member function 'int bar::barf(X)':
  test.cpp:14: error: expected primary-expression before 'double'
  test.cpp:14: error: expected ';' before 'double'
  test.cpp:14: error: expected unqualified-id before '>' token

Notes:

(1) Replacing the definition of bar::barf by the commented version makes
    the bug go away (the program prints out 53).

(2) The problem evidently isn't with the instantiation of bar::barf.  I
    get precisely the same error with an empty main program.

(3) Visual C++ 7.0 compiles this without complaint, so I don't think I'm
    misusing C++.

Thanks for your attention...

-- 
Charles Karney <address@hidden>
Sarnoff Corporation, Princeton, NJ 08543-5300

URL: http://charles.karney.info
Tel: +1 609 734 2312
Fax: +1 609 734 2662