Patch for template bug

[Mark Mitchell <mmitchell at usa dot net>]

Here's a bug report and (easy) fix.

  template <class S, class T>
  class mem_fun1_t {
  public:
    mem_fun1_t(S (T::*pf)(double)) {} 
  };

  template <class T>
  class mem_fun1_t<void, T> { 
  public:
    mem_fun1_t(void (T::*pf)(double)) {}
  };

  struct Operation {
    double eval(double) {}
  };

  int main() {
    mem_fun1_t<double, Operation> m(&Operation::eval);
  }

supernova% g++ -c test.cpp
test.cpp:20: sorry, not implemented: use of `void_type' in template type unification

I believe that this fix should go on the release branch: it's very low
risk, and came up for me when using STL.

-- 
Mark Mitchell		mmitchell@usa.net
Stanford University	http://www.stanford.edu

1997-11-26  Mark Mitchell  <mmitchell@usa.net>

	* pt.c (unify): Handle `void' template parameters in
	specializations.

Index: gcc/cp/pt.c
===================================================================
RCS file: /home/mitchell/Repository/egcs/gcc/cp/pt.c,v
retrieving revision 1.1.1.3
diff -c -p -r1.1.1.3 pt.c
*** pt.c	1997/11/25 00:49:42	1.1.1.3
--- pt.c	1997/11/26 19:57:02
*************** unify (tparms, targs, ntparms, parm, arg
*** 3851,3856 ****
--- 3851,3857 ----
      case COMPLEX_TYPE:
      case INTEGER_TYPE:
      case BOOLEAN_TYPE:
+     case VOID_TYPE:
        if (TREE_CODE (arg) != TREE_CODE (parm))
  	return 1;
  
Index: gcc/testsuite/g++.old-deja/g++.pt/spec1.C
===================================================================
RCS file: spec1.C
diff -N spec1.C
*** /dev/null	Mon Dec 31 20:00:00 1979
--- spec1.C	Wed Nov 26 12:00:39 1997
***************
*** 0 ****
--- 1,21 ----
+ // Build don't link:
+ 
+ template <class S, class T>
+ class mem_fun1_t {
+ public:
+   mem_fun1_t(S (T::*pf)(double)) {} 
+ };
+ 
+ template <class T>
+ class mem_fun1_t<void, T> { 
+ public:
+   mem_fun1_t(void (T::*pf)(double)) {}
+ };
+ 
+ struct Operation {
+   double eval(double) {}
+ };
+ 
+ int main() {
+   mem_fun1_t<double, Operation> m(&Operation::eval);
+ }