Rich Johnson <rjohnson@xxxxxxxxxxxxxxxxxxxxxxx> writes:
| Hi folks--
|
| Compiling the following (with no options) produces an ambiguity error:
| >>file: bug.cpp >>>>>>>>>
| struct C1 { void f( double ){}; };
| struct C2 { void f( int ){}; };
|
| class M : public C1, public C2 {};
|
| int main()
| {
| double c1;
| M m;
| m.f(c1);
| }
| <<<<<<<<<<<<<<<<<
| The specific error report is:
| $ g++ bug.cpp -o bug
| bug.cpp: In function `int main()':
| bug.cpp:11: error: request for member `f' is ambiguous
| bug.cpp:2: error: candidates are: void C2::f(int)
| bug.cpp:1: error: void C1::f(double)
|
| I've tried both g++(4.0.0 20041026) on Mac OS X 10.4.4, g++(4.0.3
| 20051201) on debian(powerpc) unstable. and g++-3.3.6 (Debian
| 1:3.3.6-10). All three report the same error.
|
| Is the code proper C++? If not, what am I missing?
| Given that there's there's only one method with a ''void f(double)"
| signature where's the source of the ambiguity?
The program is indeed in error. There are two kinds of ambiguity:
(1) name lookup ambiguity
(2) call ambiguity.
Since overload resolution takes place only after name lookup, you
can't expect overload resolution to pick C1::f, when you're already in
trouble with (1).
-- Gaby
