Debug prints in @nogc

[Yuxuan Shui via Digitalmars-d-learn]

On Wednesday, 31 August 2016 at 19:39:36 UTC, ag0aep6g wrote:
> On 08/31/2016 09:23 PM, Yuxuan Shui wrote:
>> Correct me if I'm wrong. But I believe this is only true when 
>> the source
>> code of function is not available. Otherwise the compiler 
>> should always
>> know if a function is actually @nogc or not.
>
> Attributes are only inferred in certain cases where the source 
> code must be available anyway (templates, `auto` return value). 
> For ordinary functions, the compiler only considers them @nogc 
> when they're explicitly marked.
>
> For example, the compiler won't let you do this, even though 
> f's source code is available and it's obviously de-facto @nogc:
>
> ----
> void f() {}
> void main() @nogc { f(); }
> ----

That's a good point. By IMHO, all the (non-template) function in 
Phobos that can be marked @nogc, should be marked @nogc, 
otherwise it's a bug. If the function is in your own code, you 
should use @nogc, not assumeNogc.

After a second thought, the real use case of assumeNogc is 
probably virtual functions. But then again, it is kind of 
dangerous to use it even in this case.