I was playing with __traits and tried the code below.
Shouldn't the compiler emit a warning that I'm defining isPOD
multiple times and/or I'm defining something that is built-in
like isPOD?

// DMD64 D Compiler v2.069
import std.stdio;

struct isPOD {
bool status = false;
}

int main()
{
    byte isPOD = 0;
    writeln(isPOD);
    writeln(__traits(isPOD, typeof(isPOD)));
    return 0;
}

On 12.11.2015 06:27, ric maicle wrote:
> I was playing with __traits and tried the code below.
> Shouldn't the compiler emit a warning that I'm defining isPOD
> multiple times and/or I'm defining something that is built-in
> like isPOD?
>
> // DMD64 D Compiler v2.069
> import std.stdio;
>
> struct isPOD {
> bool status = false;
> }
>
> int main()
> {
>      byte isPOD = 0;
>      writeln(isPOD);
>      writeln(__traits(isPOD, typeof(isPOD)));
>      return 0;
> }

__traits has special syntax. The first "argument" must be from a list of special keywords that only have special meaning in that place. You can't put the name of a struct there, and you can't put the special keyword anywhere else. So there's no ambiguity, and you're not redefining anything. Everything's fine.

On Thursday, 12 November, 2015 07:50 PM, anonymous wrote:
> __traits has special syntax. The first "argument" must be from a list of
> special keywords that only have special meaning in that place. You can't
> put the name of a struct there, and you can't put the special keyword
> anywhere else. So there's no ambiguity, and you're not redefining
> anything. Everything's fine.

Thanks for clarifying __traits.

On another thing. I'm wondering why the compiler didn't issue a warning
on struct isPOD and byte isPOD? Isn't this called 'shadowing' or have I
misunderstood the term?

On Thursday, 12 November 2015 at 15:06:26 UTC, ric maicle wrote:
> On Thursday, 12 November, 2015 07:50 PM, anonymous wrote:
>> __traits has special syntax. The first "argument" must be from a list of
>> special keywords that only have special meaning in that place. You can't
>> put the name of a struct there, and you can't put the special keyword
>> anywhere else. So there's no ambiguity, and you're not redefining
>> anything. Everything's fine.
>
> Thanks for clarifying __traits.
>
> On another thing. I'm wondering why the compiler didn't issue a warning
> on struct isPOD and byte isPOD? Isn't this called 'shadowing' or have I
> misunderstood the term?

If I remember correctly:

Shadowing globals is allowed, all other instances of shadowing are not.