Broken function reference error?

[AWLaFramboise@aol.com]

Hi,

I have run across a weird peculiarity with regards to references to functions
in C++.  The following code segment compiles and runs without problems, unless
you uncomment the inst_ref line.

---
template<typename function>
class myclass {
  public:
    myclass(function f) : func(f) {
    }
    function func;
};


template<typename function>
myclass<function> inst_value(function f) {
  return myclass<function>(f);
}


template<typename function>
myclass<function> inst_ref(function &f) {
  return myclass<function>(f);
}


void myfunction() {
}


int main() {
  inst_value(myfunction);
//  inst_ref(myfunction);
  // uncomment the preceding line to get the weird error

  return 0;
}
---

I'm using gcc 3.2 mingw on mingw/sys.  Compiled with:
g++ -ansi -pedantic -Wall -W -Wfloat-equal -Wundef -Wshadow -Wpointer-arith -
Wcast-qual -Wcast-align -Wwrite-strings -Wold-style-cast -Woverloaded-virtual -
Wsign-promo -Wpacked -g3 -o functest functest.cpp

I get this diagnostic when compiling with the line uncommented:
functest.cpp: In instantiation of `myclass<void ()()>':
functest.cpp:28:   instantiated from here
functest.cpp:6: field `myclass<void ()()>::func' invalidly declared function 
   type

Apparently, there is a difference in type between these two templates, but
GCC does not show it in any of the diagnostics (as far as I can see).
Whatever difference there is causing it to work with one, but not another,
and the error message is vague.  Either way, I do not understand.  If having
a function data member was a problem, I'd think that a non-ref function would
be a problem, not a ref.

Can someone help me figure out whats going wrong?


Thanks,

Aaron W. LaFramboise
awlaframboise@aol.com