[boost] Re: CLA/Config file library opinion

From: Gennadiy Rozental (gennadiy.rozental_at_[hidden])
Date: 2003-05-28 17:34:24

> While I don't find the interface proposed by Vladimir to be offensive,
> when you get a pile of function arguments of the same type together a
> named parameter interface *can* be a help.  I don't think I'd use
> operator<<, though.  If it's really about readability I'd tend to
> sacrifice some non-intrusive extensibility for a cleaner syntax:
>
>      parameter<std::string>( "output" )
>        .place_to( output_file_name )
>        .default_value( "/tmp/abc" )
>        .description( "output file name" )
>        ;

I showed example out of context.

In fact my interface would look like this:
    cla::parser<...> p;
     p << ignore_mismatch
        << named_option( "version" )
                << place_to( show_version  )
                << description( "...")
       << named_parameter<int>( "trace_level" )
                << default_value( 1 )
                << place_to( g_trace_level )
                << description( "...")
...

template<typename T>operator<<( cla::parser<...>, T& ) is the only interface
currently supported for both parameters and modifiers.

I may consider other propositions.

> But anyway, neither of these looks like a huge win over a function
> which simply takes 3 parameters.  Probably the complexity isn't
> justified.

There maybe significantly more modifiers for parameter. For example:
optional, multiplicable, separator. Now you need to deal with 7 values.
Also I in fact believe that my version is simpler, cause only one interface
function required.

> Dave Abrahams

Gennadiy.