Thread: [Cppcms-users] init(content::base &) can't be used in derived class of cppcms::application

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cppcms-users

[Cppcms-users] init(content::base &) can't be used in derived class of cppcms::application

From: kpeo <sla...@ya...> - 2011-01-30 14:41:37

Hello Artyom and all!

As i understood correctly, function like init(content::base &) can't be used now in derived class of cppcms::application since r1653 of cppcms/url_dispatcher.h, where new  init() is now used. 
So we should to rename our init(content::base &) function to ini(content::x &) for example, to avoid compile errors like:

/usr/local/include/cppcms/url_dispatcher.h: In constructor ‘cppcms::url_dispatcher::page_guard<C, typename booster::enable_if<booster::is_base_of<cppcms::application, C>, void>::type>::page_guard(C*) [with C = app::project]’:
/usr/local/include/cppcms/url_dispatcher.h:210:   instantiated from ‘void cppcms::url_dispatcher::binder0<C>::operator()() const [with C = app::project]’
/usr/local/include/booster/function.h:163:   instantiated from ‘void booster::function<Result()>::callable_impl<void, F>::call() [with F = cppcms::url_dispatcher::binder0<app::project>, Result = void]’
/media/opnp/project.cpp:161:   instantiated from here
/usr/local/include/cppcms/url_dispatcher.h:187: error: no matching function for call to ‘app::project::init()’
/media/opnp/project.cpp:49: note: candidates are: void app::project::init(content::base&)

/media/opnp/project.cpp:161 - end '}' of "namespace app {"

/media/opnp/project.cpp:49:

46: project::project(site &s) :     base(s)
47: {
48: //
49: w.dispatcher().assign("^/?project/?(\\w+)?/?$",&project::out,this,1);

So, i understand correctly and this is not a bug?

Re: [Cppcms-users] init(content::base &) can't be used in derived class of cppcms::application

From: Artyom <art...@ya...> - 2011-01-30 15:20:32

Hello,

There were new virtual member functions where added
to cppcms::application:

  void init()
  void clear();

That are called upon URL Dispatching automatically.

Because you have your own init(foo &) it overloads application::init and 
actually
hides it.

   Because:
      struct foo {
         void init();
      }

      struct bar : public foo {
         void init( int y);
      }

   Then:

      bar b;
      b.init() -- illegal as it hidden by overloaded version
      you need to add 

      struct bar : public foo {
         void init( int y);
         void init() { foo::init(); }
      }

So simplest thing you can do is to add to your app

   void init() {} if you don't use it at all

Or better 

   void init() { my_parent_class::init(); }

So it would not be unhidden.

All this for support of additional programming
style when your application and context can be the same
object which may be very convenient because it allows
to access much more powerful tools from view.

See exaples/message_board


In the second thought..

I can fix it so it would work with overloading.

Take rev. 1659, it should work fine.

Artyom



----- Original Message ----
> From: kpeo <sla...@ya...>
> To: cpp...@li...
> Sent: Sun, January 30, 2011 4:41:20 PM
> Subject: [Cppcms-users] init(content::base &) can't be used in derived class of 
>cppcms::application
> 
> Hello Artyom and all!
> 
> As i understood correctly, function like  init(content::base &) can't be used 
>now in derived class of  cppcms::application since r1653 of 
>cppcms/url_dispatcher.h, where new   init() is now used. 
>
> So we should to rename our init(content::base &)  function to ini(content::x &) 
>for example, to avoid compile errors  like:
> 
> /usr/local/include/cppcms/url_dispatcher.h: In constructor  
>‘cppcms::url_dispatcher::page_guard<C, typename  
>booster::enable_if<booster::is_base_of<cppcms::application, C>,  
>void>::type>::page_guard(C*) [with C =  app::project]’:
> /usr/local/include/cppcms/url_dispatcher.h:210:    instantiated from ‘void 
>cppcms::url_dispatcher::binder0<C>::operator()()  const [with C =  
>app::project]’
> /usr/local/include/booster/function.h:163:   instantiated  from ‘void 
>booster::function<Result()>::callable_impl<void,  F>::call() [with F = 
>cppcms::url_dispatcher::binder0<app::project>,  Result = void]’
> /media/opnp/project.cpp:161:   instantiated from  here
> /usr/local/include/cppcms/url_dispatcher.h:187: error: no matching  function 
>for call to ‘app::project::init()’
> /media/opnp/project.cpp:49: note:  candidates are: void  
>app::project::init(content::base&)
> 
> /media/opnp/project.cpp:161 - end  '}' of "namespace app {"
> 
> /media/opnp/project.cpp:49:
> 
> 46:  project::project(site &s) :     base(s)
> 47: {
> 48: //
> 49:  w.dispatcher().assign("^/?project/?(\\w+)?/?$",&project::out,this,1);
> 
> So,  i understand correctly and this is not a  bug?
> 
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Re: [Cppcms-users] init(content::base &) can't be used in derived class of cppcms::application

From: kpeo <sla...@ya...> - 2011-01-30 17:50:27

Thank you for so detailed information and fast answer!
I take last revision (1661) and all works fine!

Also, think too that using new init functions in cppcms::application be more clear and convenient way for future use.

30.01.2011, 18:20, "Artyom" <art...@ya...>:
> Hello,
>
> There were new virtual member functions where added
> to cppcms::application:
>
>   void init()
>   void clear();
>
> That are called upon URL Dispatching automatically.
>
> Because you have your own init(foo &) it overloads application::init and
> actually
> hides it.
>
>    Because:
>       struct foo {
>          void init();
>       }
>
>       struct bar : public foo {
>          void init( int y);
>       }
>
>    Then:
>
>       bar b;
>       b.init() -- illegal as it hidden by overloaded version
>       you need to add
>
>       struct bar : public foo {
>          void init( int y);
>          void init() { foo::init(); }
>       }
>
> So simplest thing you can do is to add to your app
>
>    void init() {} if you don't use it at all
>
> Or better
>
>    void init() { my_parent_class::init(); }
>
> So it would not be unhidden.
>
> All this for support of additional programming
> style when your application and context can be the same
> object which may be very convenient because it allows
> to access much more powerful tools from view.
>
> See exaples/message_board
>
> In the second thought..
>
> I can fix it so it would work with overloading.
>
> Take rev. 1659, it should work fine.
>
> Artyom
>
> ----- Original Message ----
>
>>  From: kpeo <sla...@ya...>;
>>  To: cpp...@li...
>>  Sent: Sun, January 30, 2011 4:41:20 PM
>>  Subject: [Cppcms-users] init(content::base &) can't be used in derived class of
>> cppcms::application
>>
>>  Hello Artyom and all!
>>
>>  As i understood correctly, function like  init(content::base &) can't be used
>> now in derived class of  cppcms::application since r1653 of
>> cppcms/url_dispatcher.h, where new   init() is now used.
>>
>>  So we should to rename our init(content::base &)  function to ini(content::x &)
>> for example, to avoid compile errors  like:
>>
>>  /usr/local/include/cppcms/url_dispatcher.h: In constructor
>> ‘cppcms::url_dispatcher::page_guard<C, typename
>> booster::enable_if<booster::is_base_of<cppcms::application, C>,
>> void>::type>::page_guard(C*) [with C =  app::project]’:
>>  /usr/local/include/cppcms/url_dispatcher.h:210:    instantiated from ‘void
>> cppcms::url_dispatcher::binder0<C>::operator()()  const [with C =
>> app::project]’
>>  /usr/local/include/booster/function.h:163:   instantiated  from ‘void
>> booster::function<Result()>::callable_impl<void,  F>::call() [with F =
>> cppcms::url_dispatcher::binder0<app::project>,  Result = void]’
>>  /media/opnp/project.cpp:161:   instantiated from  here
>>  /usr/local/include/cppcms/url_dispatcher.h:187: error: no matching  function
>> for call to ‘app::project::init()’
>>  /media/opnp/project.cpp:49: note:  candidates are: void
>> app::project::init(content::base&)
>>
>>  /media/opnp/project.cpp:161 - end  '}' of "namespace app {"
>>
>>  /media/opnp/project.cpp:49:
>>
>>  46:  project::project(site &s) :     base(s)
>>  47: {
>>  48: //
>>  49:  w.dispatcher().assign("^/?project/?(\\w+)?/?$",&project::out,this,1);
>>
>>  So,  i understand correctly and this is not a  bug?
>>
>>  ------------------------------------------------------------------------------
>>  Special  Offer-- Download ArcSight Logger for FREE (a $49 USD value)!
>>  Finally, a  world-class log management solution at an even better price-free!
>>  Download  using promo code Free_Logger_4_Dev2Dev. Offer expires
>>  February 28th, so  secure your free ArcSight Logger TODAY!
>>  http://p.sf.net/sfu/arcsight-sfd2d
>>  _______________________________________________
>>  Cppcms-users  mailing list
>>  Cpp...@li...
>>  https://lists.sourceforge.net/lists/listinfo/cppcms-users
>
> ------------------------------------------------------------------------------
> Special Offer-- Download ArcSight Logger for FREE (a $49 USD value)!
> Finally, a world-class log management solution at an even better price-free!
> Download using promo code Free_Logger_4_Dev2Dev. Offer expires
> February 28th, so secure your free ArcSight Logger TODAY!
> http://p.sf.net/sfu/arcsight-sfd2d
> _______________________________________________
> Cppcms-users mailing list
> Cpp...@li...
> https://lists.sourceforge.net/lists/listinfo/cppcms-users