Re: Hidden overloaded operator in multiple inheritance
"Alex Blekhman" wrote:
[...] The same behaviour can be demonstrated with
following simple example:
class A
{
public:
int operator+(int) { return 42; }
};
class B
{
public:
double operator+(double) { return 3.14; }
};
class C : public A, public B
{
};
int main()
{
C c1;
int i = 5;
double d = 10.5;
c1 + i; // Error!
c1 + d; // Error!
return 0;
}
I applied SP1 for my VC++ 2005 Pro and tweaked the above
code a little bit. First of all, the code with templates
from OP still doesn't compile with the same errors as before
application of SP1.
Second, I think that VC++ actually does have a bug in call
resolving mechanism. The function name from left base class
`A' actually hides the name from right base class `B'
instead of competing with it for inclusion in name lookup
set. The above code compiles with warning that double is
implicitly converted to int. So, obviously `int A::operator+
(int)' kicked in. If I replace double in class' B `operator
+' with `char*', for example, then I get C2679 ("no
appropriate operator found").
Comeau compiler correctly reports ambiguity error in any
case (double or char*).
Alex
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