c++/9440: [3.4 regression] error message about "non-lvalue in unary '&'" when using ?: operator

[Andrew Pollard]

The following reply was made to PR c++/9440; it has been noted by GNATS.

From: Andrew Pollard <andrewp@andypo.net>
To: bangerth@dealii.org, andrew@andypo.net, gcc-bugs@gcc.gnu.org,
   gcc-gnats@gcc.gnu.org
Cc:  
Subject: Re: c++/9440: [3.4 regression] error message about "non-lvalue in unary '&'" when using ?: operator
Date: Tue, 28 Jan 2003 18:16:44 GMT

 bangerth@dealii.org replied:
 
 >    Confirmed. The problem is the lack of a copy constructor,
 >    but the message is profoundly unhelpful in detecting this.
 
 I don't think a copy constructor should have anything to do with it.
 Doesn't the compiler synthesize a copy constructor if there isn't
 one defined?
 
 Anyway, even if I add one, I still get the error...
 
 odd.cxx:
 --------------
 struct A {
     explicit A(int = 0);
     A(const A&);
     operator int() const;
 };
 
 A
 bar(bool b, const A& a)
 {
     return (b ? A() : a);
 }
 --------------
 
 % g++34 -c odd.cxx
 odd.cxx: In function `A bar(bool, const A&)':
 odd.cxx:10: error: non-lvalue in unary `&'
 
 Andrew.