Explain function syntax

[Ali Çehreli]

On 9/18/25 10:18 PM, Steven Schveighoffer wrote:
 > On Thursday, 18 September 2025 at 18:10:13 UTC, Ali Çehreli wrote:

 >>     // Not a delegate:
 >>     static assert(is (typeof(twice) == function));

 > You are mistaking the is expression for a function test with the
 > function pointer type.

I disagree because it is impossible to mistake much from the 
documentation of the is expression:

   https://dlang.org/spec/expression.html#is_expression

I stress strongly that there is not enough information there to take 
anything incorrectly. The reader has to construct a consistent mental 
model from that documentation. I did and my mental model is intact.

I did test with 'function' against 'delegate' and it worked as I still 
understand it. For the example I wrote, 'is' expression succeeds for 
'function' but not for 'delegate' if the nested function makes use of 
local scope.

Ali