Re: [boost] [flyweight] new draft uploaded at vault

From: Matias Capeletto (matias.capeletto_at_[hidden])
Date: 2006-07-17 11:15:09

> * Do you deem the lib worth eventually proposing to Boost?

Yes!

> * Do you like the usage interface?

Very much...
However, as i will like it even more if the principal class name were
easier to write, I am not a native English speaker and the ht, th
kills me :)
What about something like Boost.Flyweight / boost::flyweight / fw ?
The code is cleaner this way.

 > * Are you OK with the design concepts, in particular with the concepts
> around factories and holders?

This is one of the strong point of the library. This makes it very flexible.
I like the design a lot.

> * Have you been able to use it?

Yes, with Linux/gcc4, no problems...

> * Improvements/extensions?

I think that one nice thing to have is the ability to interact
directly with the factories.
I would like to be able, at least for debugging purpose but I have in mind some
other scenarios, to write something like:

struct names {};

struct user
{
     flyweight< std::string, tag<names>, set_factory > name;
     int age;
};

flyweight_factory< names >::instance().insert( "Joaquin" );
flyweight_factory< names >::instance().insert( "Penelope" );

...
...

std::for_each( flyweight_factory< names >::instance().begin(),
                       flyweight_factory< names >::instance().end(),
                       std::ostream_inserter< std::string >( cout ) );

If I have this feature I will be able to use a flyweight to create a
translation table for my
program.

I simple defined a map from English to "other language" phrases
bindings (pb) and uses it as my assoc_container_factory. (some details
maybe need to be tunned but the idea is simple)

I can now write:

struct translations {};

typedef flyweight
<
    std::string,
    tag< translations >,
    assoc_container_factory< tunned_map<std::string,std::string> >

> tr;

...

fileMenu.set_text( "File" ); // set_text takes a tr object

...

void ChangeLanguageToSpanish()
{
      flyweight_factory< translations >::instance()[ "File" ] = "Archivo";
      ...
};

Is this possible?

Thanks for yet another great library!
Best regards
Matias Capeletto