Bug 21580 – The D compiler adds an extra (void*) member in unittest

Status
RESOLVED
Resolution
DUPLICATE
Severity
enhancement
Priority
P1
Component
dmd
Product
D
Version
D2
Platform
x86_64
OS
Linux
Creation time
2021-01-25T08:56:05Z
Last change time
2021-01-25T12:27:38Z
Assigned to
No Owner
Creator
cbleser

Attachments

IDFilenameSummaryContent-TypeSize
1814unittest_odd_void_ptr.dExampleapplication/x-dsrc469

Comments

Comment #0 by cr — 2021-01-25T08:56:05Z
Created attachment 1814 Example I discovered something odd when I put a struct into an unittest. If you place a struct inside an unittest with a mixin template the compiler adds an extract (void*) element to the struct. carsten@spaceship:/tmp> dmd unittest_odd_void_ptr.d -unittest (int, string) (int, string, void*) (int, string) carsten@spaceship:/tmp> ldc2 unittest_odd_void_ptr.d -unittest (int, string) (int, string, void*) (int, string) See the attached code. It is not a practical problem. I just found it a little odd and properly there is an explanation. Keep up the good work. Best Regards Carsten
Comment #1 by simen.kjaras — 2021-01-25T12:27:38Z
This is mostly expected. When a nested struct has a method, that method has access to the context of the function in which it is defined, so you can do things like this: void fun() { int i = 0; struct S { void gun() { ++i; } } S s; s.gun(); assert(i == 1); } Since the nested struct may be passed to other functions or even returned from the function that created it, this context pointer needs to be embedded in the struct. Regardless, in your case the context pointer is strictly unnecessary, and could be elided. That makes this issue a duplicate of issue 10276. The workaround for this issue is to mark the struct as static. *** This issue has been marked as a duplicate of issue 10276 ***