Re: Problem using struct with copy constructor with betterC

[jfondren via Digitalmars-d-learn]

On Saturday, 6 November 2021 at 17:24:07 UTC, tchaloupka wrote:

When built with `-betterC` switch (dmd as ldc2 works with it).

I get just:
```
Error: `TypeInfo` cannot be used with -betterC
```

Well imagine getting this useful info in a large codebase :/


Looks like https://issues.dlang.org/show_bug.cgi?id=20715


BetterC is great, but a bit of a minefield to use.


The blame might be more on copy constructors, here. This also 
fails:


https://issues.dlang.org/show_bug.cgi?id=20365

Problem using struct with copy constructor with betterC

[tchaloupka via Digitalmars-d-learn]

After a long fiddling with a code that won't compile I've got 
this test case:


```D
struct Foo {
this(ref return scope Foo rhs) {}
~this() {}
}

struct Bar {
@disable this(this);
Foo[2] foos;
}

extern (C)
void main() {}
```

When built with `-betterC` switch (dmd as ldc2 works with it).

I get just:
```
Error: `TypeInfo` cannot be used with -betterC
```

Well imagine getting this useful info in a large codebase :/

Anyway, I've traced the problem by custom built dmd using 
`printf` logging here: 
https://github.com/dlang/dmd/blob/a6f49dade85452d61d9ebcf329e2567ecacd5fab/src/dmd/e2ir.d#L2606


So it somehow tries to generate `_d_arrayctor` for the static 
array.


I've tried to add `= void` to the array, but it doesn't help.
Is it a bug (probably is) and are there any workaround for this?

If I remove copy constructor or destructor form `Foo`, it 
compiles. But I need them there..


BetterC is great, but a bit of a minefield to use.