http://gcc.gnu.org/bugzilla/show_bug.cgi?id=57614
Bug ID: 57614
Summary: Friend declaration and qualified class member access
Product: gcc
Version: 4.7.3
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: roger.ferrer at bsc dot es
In the snippet below, a weird interaction happens between two overloaded friend
declarations and a class member access using a qualified id-expression.
// -- test.cc
class A
{
protected:
int s;
public:
A();
};
class B : public A
{
protected:
public:
B();
// By reversing the order of these two declarations
// you can change the location of the error
friend void foo(B &, int);
friend void foo(B &, B& b);
};
void foo(B& a, int)
{
// This is only fine if this function was the first "friend" declared
a.A::s = 3;
// Always fine
a.s = 3;
}
void foo(B& a, B& b)
{
// This is only fine if this function was the first "friend" declared
a.A::s = 3;
// Always fine
a.s = 3;
}
// -- end of test.cc
g++ is 4.7.3
$ g++ -c test.cc
test.cc: In function ‘void foo(B&, B&)’:
test.cc:4:7: error: ‘int A::s’ is protected
test.cc:32:7: error: within this context
If we reverse the order of the friend declarations we can change the error
location.
$ g++ -c test.cc
test.cc: In function ‘void foo(B&, int)’:
test.cc:4:7: error: ‘int A::s’ is protected
test.cc:24:7: error: within this context
The error seems to happen with the second overloaded friend declaration.
This problem can be worked around if the id-expression of the class member
access is unqualified.
