Re: [Boost-users] Boost.Signals example/doc_view application question

From: Wu Yinghui, Freddie (yhwu_at_[hidden])
Date: 2006-08-04 21:50:25

[snip]
> The View abstract base class requires concrete bases to provide a
> concrete implementation of the refresh() member function matching the
> slot signature required.
> 
> class View
> {
> public:
>     virtual void refresh(bool) const = 0;
>     // ...
> };
> 
> Here's my problem.  If I change the signal to take no args using the
> preferred or portable syntax I get compilation errors:
> 
> class Document
> {
> public:
>     typedef boost::signal< void () >  signal_t;
>     // ...
> 
>     void append(const char* s)
>     {
>         m_text += s;
>         m_sig(true);
You should use
          m_sig();
instead!

>     }
>     // ...
> };
> 
> class View
> {
> public:
>     virtual void refresh() const = 0;
>     // ...
> };
> 
> Compilation output (msvc-7.1):
> 
> Compiling...
> SignalTest.cpp
> c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2825:
> 'F::result_type': cannot form a qualified name
>         c:\Boost\include\boost-1_33_1\boost\bind\bind_template.hpp(15) :
> see reference to class template instantiation
> 'boost::_bi::result_traits<R,F>' being compiled
>         with
>         [
>             R=boost::_bi::unspecified,
>             F=void (__thiscall View::* )(void) const
>         ]
>         c:\development\SignalTest\SignalTest.cpp(49) : see reference to
> class template instantiation 'boost::_bi::bind_t<R,F,L>' being compiled
>         with
>         [
>             R=boost::_bi::unspecified,
>             F=void (__thiscall View::* )(void) const,
>             L=boost::_bi::list2<boost::_bi::list_av_2<View
> *,boost::arg<1>>::B1,boost::_bi::list_av_2<View *,boost::arg<1>>::B2>
>         ]
> c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2039:
> 'result_type' : is not a member of 'operator``global namespace'''
> c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2146: syntax
> error : missing ';' before identifier 'type'
> c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : error C2955:
> 'boost::_bi::type' : use of class template requires template argument list
>         c:\Boost\include\boost-1_33_1\boost\bind.hpp(112) : see
> declaration of 'boost::_bi::type'
> c:\Boost\include\boost-1_33_1\boost\bind.hpp(63) : fatal error C1903:
> unable to recover from previous error(s); stopping compilation

Cheers,

Freddie