Why typedef's shouldn't have been removed :(

[Gor Gyolchanyan]

mixin template TypeDef(Type, string name, Type init)
{
    mixin(`struct `~name~` { public alias _impl this; private Type
_impl = init; };`);
}

unittest
{
    mixin TypeDef!(int, `MyInt`, 5);

    MyInt mi;

    assert(typeid(myInt) != typeid(int));
    assert(mi == 5);
}

On Sat, May 5, 2012 at 3:09 PM, bearophile <bearophileHUGS at lycos.com> wrote:
> Mehrdad:
>
>> Now it's impossible to figure out whether a ParameterTypeTuple contains an
>> HWND versus an HGDIOBJ or whatever...
>>
>> this should really be fixed...
>
>
> typedef is a quite useful feature, but the one present in D was
> unsound/broken, especially in presence of OOP. Fixing language features is
> hard (people didn't seem to understand that typedef is not meant to be used
> with classes), once their semantics is defined, it's quite hard to fix it.
> But adding features to D/Phobos is much simpler. So once there is a clear
> and sound design for what this feature has to do and its semantics, I expect
> to see in D a way to do the same things. Currently the Typedef in Phobos is
> more broken than the built-in typedef. Here the Ada language is a good
> reference to copy from. So the idea of removing typedef was good iff we
> eventually have something good to replace it.
>
> Bye,
> bearophile



-- 
Bye,
Gor Gyolchanyan.