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Q&A typeof_unqual behaves differently in gcc and clang

C23 6.7.3.6 contains this (informative) example demonstrating the use of typeof_unqual: const char* const animals[] = { "aardvark", "bluejay", "catte", }; typeof_unqual(animals) anima...

1 answer · posted 16d ago by Lundin‭ · edited 16d ago by hkotsubo‭

Question c gcc clang c23 typeof

#2: Post edited by

hkotsubo‭ · 2024-11-26T13:00:59Z (16 days ago)
fix typo

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typeof_unqual behaves differently in gcc and clang

~~C23 6.7.3.6 contains this (informative) example demonstating the use of `typeof_unqual`:~~
```c
const char* const animals[] = {
"aardvark",
"bluejay",
"catte",
};
typeof_unqual(animals) animals2_array[3];
```
And this is supposedly equivalent to `const char* animals2_array[3];` according to the example. That is also the result I get from clang 19.1.
But in gcc 14.2 I get the type `const char* const [3]`.
Full example: https://godbolt.org/z/Gf9M43nrM
What is correct? Is the standard unclear? The parts about `typeof_unqual` in 6.7.3.6 do not mention arrays at all.

C23 6.7.3.6 contains this (informative) example demonstrating the use of `typeof_unqual`:
```c
const char* const animals[] = {
"aardvark",
"bluejay",
"catte",
};
typeof_unqual(animals) animals2_array[3];
```
And this is supposedly equivalent to `const char* animals2_array[3];` according to the example. That is also the result I get from clang 19.1.
But in gcc 14.2 I get the type `const char* const [3]`.
Full example: https://godbolt.org/z/Gf9M43nrM
What is correct? Is the standard unclear? The parts about `typeof_unqual` in 6.7.3.6 do not mention arrays at all.

c gcc clang c23 typeof

#1: Initial revision by

Lundin‭ · 2024-11-26T11:56:38Z (16 days ago)

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typeof_unqual behaves differently in gcc and clang

C23 6.7.3.6 contains this (informative) example demonstating the use of `typeof_unqual`:

```c
const char* const animals[] = {
  "aardvark",
  "bluejay",
  "catte",
};

typeof_unqual(animals) animals2_array[3];
```

And this is supposedly equivalent to `const char* animals2_array[3];` according to the example. That is also the result I get from clang 19.1. 

But in gcc 14.2 I get the type `const char* const [3]`. 

Full example: https://godbolt.org/z/Gf9M43nrM

What is correct? Is the standard unclear? The parts about `typeof_unqual` in 6.7.3.6 do not mention arrays at all.

c gcc clang c23 typeof

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