• aliak (32/32) Sep 03 2018 In another thread [0] this function can be used to call non nogc
• Paul Backus (5/8) Sep 03 2018 You can't define an impure function inside a pure unittest. If
• aliak (3/12) Sep 04 2018 Seems you be right. Hmm, I wonder if it's a bug because you can

aliak <something something.com> writes:

In another thread [0] this function can be used to call non nogc 
code from nogc code

import std.traits;

auto assumeNoGC(T)(T t) {
     enum attrs = functionAttributes!T | FunctionAttribute.nogc;
     return cast(SetFunctionAttributes!(T, functionLinkage!T, 
attrs)) t;
}

And then you can use it like:

 nogc unittest {
   auto allocate() {
     return [1];
   }
   assumeNoGC({allocate;})();
}

So I tried to the same with pure, wrote assumePure and changed 
the attribute to FunctionAttribute.pure_, but that doesn't seem 
to be treated the same:

pure unittest {
   static int thing = 3;
   void modify() {
     thing = 4;
   }
   assumePure({modify;})();
}

Ye get: pure function modify cannot access mutable static data 
thing

Why does it work with nogc but not with pure?

Cheers,
- Ali

[0]: 
https://forum.dlang.org/thread/awalwokejtywzkxgdqyg forum.dlang.org

Paul Backus <snarwin gmail.com> writes:

On Monday, 3 September 2018 at 22:07:10 UTC, aliak wrote:
 Why does it work with nogc but not with pure?

 Cheers,
 - Ali

You can't define an impure function inside a pure unittest. If 
you move `modify` outside the unittest block, and change the 
argument from a lambda to a function pointer, it works:

https://run.dlang.io/is/xRS75H

aliak <something something.com> writes:

On Tuesday, 4 September 2018 at 01:33:52 UTC, Paul Backus wrote:
 On Monday, 3 September 2018 at 22:07:10 UTC, aliak wrote:
 Why does it work with nogc but not with pure?

 Cheers,
 - Ali

 You can't define an impure function inside a pure unittest. If 
 you move `modify` outside the unittest block, and change the 
 argument from a lambda to a function pointer, it works:

 https://run.dlang.io/is/xRS75H

Seems you be right. Hmm, I wonder if it's a bug because you can 
define a non-nogc function inside a nogc block :/