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July 22, 2012
Compile-Time module info
Is there any means to get meaningful moduleinfo at compile time, 
specifically a list of the local classes of a given module?  
__traits(allMembers, mod) doesn't work: "inverse.d(109): Error: 
import data has no members".

I was hoping that something along these lines would be possible 
in CTFE:

foreach ( decl ; __traits( allMembers, data ) ) {
    if ( is( typeof( mixin( decl ) ) == class )
    && !__traits( isAbstractclass, mixin( decl ) ) ) {
        // ...some code in here...
    }
}


-- Chris NS
July 22, 2012
Re: Compile-Time module info
On Sun, Jul 22, 2012 at 9:31 AM, Chris NS <ibisbasenji@gmail.com> wrote:
> Is there any means to get meaningful moduleinfo at compile time,
> specifically a list of the local classes of a given module?
> __traits(allMembers, mod) doesn't work: "inverse.d(109): Error: import data
> has no members".
>
> I was hoping that something along these lines would be possible in CTFE:
>
> foreach ( decl ; __traits( allMembers, data ) ) {
>     if ( is( typeof( mixin( decl ) ) == class )
>     && !__traits( isAbstractclass, mixin( decl ) ) ) {
>         // ...some code in here...
>     }
> }

The catch is that __traits(allMembers, symbol) does not work on a
simple module name (as in "module foo;"). It does work on composite
module names (as in "module std.algorithm;" or "module
mypackage.mymodule;"). I don't know if that's a bug or if that fact
that __traits(allMembers, ...) works on a module is an unexpected
loophole.

Anyway, IIRC, I give code to do that in an online tutorial on templates, here:

https://github.com/PhilippeSigaud/D-templates-tutorial/blob/master/dtemplates.pdf?raw=true

The code predates a few recent addition to std.traits, so it could
possibly made shorter now, I don't know.
Read from p.114 (20.3) and following. I guess what you need is section
20.7, p. 118+.

The code from all examples should be in a directory on Github, also.

Philippe
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