Re: A: a new bug to old plain C

LIU Hao via Gcc-help <[email protected]> Wed, 26 Nov 2025 17:46:58 +0800

Newsgroups	gmane.comp.gcc.help
Message-ID	<[email protected]>

在 2025-11-26 17:37, Александр Поваляев 写道:
> Hi there!
> 
> The code below works fine on all the GCC compilers. It doesn't provide either errors or warnings.
> 
> "
> struct zzz {
> unsigned x, y;
> };
> 
> 
> void square(struct zzz * arr_of_ptr, unsigned count) {
> 
> struct zzz * const ptr1 = arr_of_ptr; // OK!
> struct zzz const * ptr2 = arr_of_ptr; // OK!
> struct zzz const * const ptr3 = arr_of_ptr; // OK!
> 
> }
> "

These are not the same as your original code. These are pointers to 'qualified or unqualified versions of 
compatible type(s)', where the 'compatible type' is `struct zzz *`.

In your original code there's `struct zzz ** arr_of_ptr` which points to `struct zzz *`, and there's 
`struct zzz const * const * const end_of_arr` which points to const-qualified `struct zzz const *`, so 
those pointers point to incompatible different types, and are not convertible.



-- 
Best regards,
LIU Hao

OpenPGP_signature.asc (application/pgp-signature, 840 B)