Why using wrappers for D?

[Mike Wey via Digitalmars-d-learn]

On 10/03/2016 07:19 PM, Chalix wrote:
> On Monday, 3 October 2016 at 13:51:28 UTC, Mike Parker wrote:
>> // wrapfoo.d
>> import foo;  // import the foo module from above
>>
>> void myFunc(string s)
>> {
>>     import std.string : toStringz;
>>     my_func(s.toStringz());
>> }
>
> Thank you for the example, Mike!
>
> And thanks to all others who support me with their answers! I didn't
> expect so much answers, the D community seems to be very helpful :)
>
> But there still is one thing, which I don't get:
>
> If I "import foo;" in my project, it will be compiled alongside. So
> there is no need for an extra library. Same should be for wrapfoo.d. If
> I "import wrapfoo;", I should just need the C-library "foo", and no
> D-library "food" right?
>
>
> To have a more practical example, I looked up the "header" of the GtkD
> gtk/Main.d file. There are functions exactly like you described:
>
>> public static void init(ref string[] argv)
>>     {
>>         int argc = cast(int)argv.length;
>>         char** outargv = Str.toStringzArray(argv);
>>
>>         gtk_init(&argc, &outargv);
>>
>>         argv = Str.toStringArray(outargv, argc);
>>     }
>
> This function wraps the C-like gtk_init function to a D init function.
> The gtk_init function is the function from the GTK+ library, which is
> loaded in the gtkc/gtk.d file:
>> Linker.link(gtk_init, "gtk_init", LIBRARY.GTK);
> Linker and link are defined in the gtkc/Loader.d
>
> So, why is it not enough just to "import gtk.Main"? What kind of code is
> inside the gtkd-3 library?

The gtkd-3 library contains for example the code you quoted above.

-- 
Mike Wey