https://run.dlang.io/is/8LbmzG

1) why .stringof and typeid() is equal logically and different in fact? What is difference between them? Is it that stringof compile time and typeid runtime things? Anyway wouldn't it be better they will equal both logically and literally?
2) Where do these attributes come from? I mean `pure nothrow @nogc @safe` except `@property` that I set explicitly?

On Thursday, 5 October 2017 at 14:59:10 UTC, drug wrote:
> 1) why .stringof and typeid() is equal logically and different in fact? What is difference between them? Is it that stringof compile time and typeid runtime things? Anyway wouldn't it be better they will equal both logically and literally?

stringof is a static debugging aid, just a string that kinda represents it in code. It isn't guaranteed to match anything, but should be enough that when you eyeball it it points you in the right direction... you shouldn't rely on it to be anything specific. typeid, on the other hand, is a published, documented object with methods and defined comparisons. So that's one difference.

The other one is indeed compile time vs runtime: stringof is purely compile time, whereas typeid() returns a runtime object on a runtime object. To see the difference, try:

Object o = new MyClass();
typeid(o);


You'll see it is MyClass, but the static versions (stringof, typeof, etC) will all think of it as Object.


> 2) Where do these attributes come from? I mean `pure nothrow @nogc @safe` except `@property` that I set explicitly?

You didn't specify a return value for those functions, which meant the compiler inferred a bunch about it. It inferred the return value and those other attributes to fill in the gap.

If you gave an explicit return value `@property int` or `@property void`, then it wouldn't automatically fill stuff in anymore.

05.10.2017 18:04, Adam D. Ruppe пишет:
> On Thursday, 5 October 2017 at 14:59:10 UTC, drug wrote:
>> 1) why .stringof and typeid() is equal logically and different in fact? What is difference between them? Is it that stringof compile time and typeid runtime things? Anyway wouldn't it be better they will equal both logically and literally?
> 
> stringof is a static debugging aid, just a string that kinda represents it in code. It isn't guaranteed to match anything, but should be enough that when you eyeball it it points you in the right direction... you shouldn't rely on it to be anything specific. typeid, on the other hand, is a published, documented object with methods and defined comparisons. So that's one difference.
> 
> The other one is indeed compile time vs runtime: stringof is purely compile time, whereas typeid() returns a runtime object on a runtime object. To see the difference, try:
> 
> Object o = new MyClass();
> typeid(o);
> 
> 
> You'll see it is MyClass, but the static versions (stringof, typeof, etC) will all think of it as Object.
> 
> 
>> 2) Where do these attributes come from? I mean `pure nothrow @nogc @safe` except `@property` that I set explicitly?
> 
> You didn't specify a return value for those functions, which meant the compiler inferred a bunch about it. It inferred the return value and those other attributes to fill in the gap.
> 
> If you gave an explicit return value `@property int` or `@property void`, then it wouldn't automatically fill stuff in anymore.
Thank you, Adam!