Core issue 899

	Core issue 899
	* call.c (add_function_candidate): Only permit explicit conversion
	ops if copy ctor was called with a single argument.

From-SVN: r153509

gcc/cp/ChangeLog

 2009-10-23  Jason Merrill  <jason@redhat.com>
 
+	Core issue 899
+	* call.c (add_function_candidate): Only permit explicit conversion
+	ops if copy ctor was called with a single argument.
+
 	* call.c (initialize_reference): Tweak error message.
 
 2009-10-21  Jakub Jelinek  <jakub@redhat.com>

gcc/cp/call.c

@@ -1631,7 +1631,8 @@ add_function_candidate (struct z_candidate **candidates,
 	      parmtype = build_pointer_type (parmtype);
 	    }
 
-	  if (ctype && i == 0 && DECL_COPY_CONSTRUCTOR_P (fn))
+	  if (ctype && i == 0 && DECL_COPY_CONSTRUCTOR_P (fn)
+	      && (len-skip == 1))
 	    {
 	      /* Hack: Direct-initialize copy parm (i.e. suppress
 		 LOOKUP_ONLYCONVERTING) to make explicit conversion ops

gcc/testsuite/ChangeLog

+2009-10-23  Jason Merrill  <jason@redhat.com>
+
+	Core issue 899
+	* g++.dg/cpp0x/explicit4.C: New.
+
 2009-10-23  Joseph Myers  <joseph@codesourcery.com>
 
 	* g++.dg/abi/rtti3.C, g++.dg/abi/thunk4.C: Skip for *-*-mingw* and

gcc/testsuite/g++.dg/cpp0x/explicit4.C

+// Negative explicit conv test.
+// { dg-options "-std=c++0x" }
+
+struct A {
+  A(const A&, int = 0);		// { dg-message "candidates" }
+};
+struct B
+{
+  explicit operator A();
+};
+
+int main()
+{
+  B b;
+  (A(b));			// OK
+  (A(b,1));			// { dg-error "no match" }
+}