I want to add a Phobos module with template mixins for common idioms.

[Idan Arye]

On Monday, 6 May 2013 at 19:47:33 UTC, Diggory wrote:
> It's a nice idea but personally I don't like the syntax much, 
> for example it's completely non-obvious what "true" does when 
> passed to the singleton mixin, or that the parameters to the 
> property mixin are "type, name, condition, initial value".
>
> I suppose you could do something like this:
> mixin property!`int x = 1`;
>
> The other problem is that I don't think it's beneficial to 
> invite the use of mixins for such simple substitutions. I'd 
> rather see the majority of code be standard D syntax, and the 
> use of mixins be the exception rather than the rule. It's 
> similar to how excessive use of macros in C++ is generally 
> considered bad practice.

If D supported Java's annotation metaprogramming I could have 
implemented a syntax like:

     @Property(`a < 50`) int a = 1;

since it doesn't, I have to use mixin templates...

(Declaimer: I do not want to imply here that Java is a good 
language. Java is a terrible language. Annotation metaprogramming 
is it's only redeeming feature, and even that feature is far too 
complex for common use...)


Anyways, I'll have to add a new trait template to extract the 
name from the declaration(Compile time regex are too slow), but I 
think I can pull off the style you suggest. However, we still 
need an extra template argument for the verifier, something like 
this:

     mixin propertyVerified!(`int x = 1`, `a < 50`);

Is this readable enough?