[Boost-users] [function] function_equal or function::operator== ambiguous overload?

From: Hajo Kirchhoff (mailinglists_at_[hidden])
Date: 2008-08-18 09:25:24

Hello,
I would like to compare two boost::function<void()> objects, but get an
"boost::operator ==' : 4 overloads have similar conversions" error.

On Visual Studio 2008 SP1, both Win32 and x64 target platform, the
following code does not compile:

boost::function<void()> one, two;
if (one==two)
        one.clear();

I get the compile error messages below.

Any ideas, any help?

Regards and thank you in advance

Hajo

1>c:\users\hajo
kirchhoff\desktop\prj\cct2_2005\r3000trunk\v4\wbr_backend\basic_stream_connector.cpp(31)
: error C2666: 'boost::operator ==' : 4 overloads have similar conversions
1>        c:\users\hajo
kirchhoff\desktop\prj\boost\boost_1_36_0\boost\function\function_template.hpp(821):
could be 'void boost::operator ==<R>(const boost::function0<R> &,const
boost::function0<R> &)' [found using argument-dependent lookup]
1>        with
1>        [
1>            R=void
1>        ]
1>        c:\users\hajo
kirchhoff\desktop\prj\boost\boost_1_36_0\boost\function\function_base.hpp(747):
or       'bool boost::operator
==<boost::function<Signature>>(Functor,const boost::function_base &)'
[found using argument-dependent lookup]
1>        with
1>        [
1>            Signature=void (void),
1>            Functor=boost::function<void (void)>
1>        ]
1>        c:\users\hajo
kirchhoff\desktop\prj\boost\boost_1_36_0\boost\function\function_base.hpp(738):
or       'bool boost::operator ==<boost::function<Signature>>(const
boost::function_base &,Functor)' [found using argument-dependent lookup]
1>        with
1>        [
1>            Signature=void (void),
1>            Functor=boost::function<void (void)>
1>        ]
1>        or       'built-in C++ operator==(void (__thiscall
boost::function0<R>::dummy::* )(void), void (__thiscall
boost::function0<R>::dummy::* )(void))'
1>        with
1>        [
1>            R=void
1>        ]
1>        while trying to match the argument list
'(boost::function<Signature>, boost::function<Signature>)'
1>        with
1>        [
1>            Signature=void (void)
1>        ]