> IIRC Clang implements a C++ style auto, while GCC implements a C style auto, w...

flohofwoe · 2024-10-16T10:19:43 1729073983

Well, not in C :)

Here's an example where Clang and GCC don't agree about the behaviour of auto in C23:

https://www.godbolt.org/z/WchMK18vx

IIRC Clang implements 'C++ semantics' for C23 auto, while GCC doesn't.

Last time I brought that up it turned out that both behaviours are 'standard compliant', because the C23 standard explicitly allows such differing behaviour (it basically standardized the status quo even if different compilers disagreed about auto semantics in C).

PS: at least Clang has a warning now in pedantic mode: https://www.godbolt.org/z/ovj5r4axn

cpeterso · 2024-10-16T15:53:50 1729094030

> PS: at least Clang has a warning now in pedantic mode: https://www.godbolt.org/z/ovj5r4axn

Did you mean gcc? Your link shows a gcc error:

  <source>:3:5: error: 'auto' requires a plain identifier, possibly with attributes, as declarator
      3 |     auto* p = &i;
        |     ^~~~

flohofwoe · 2024-10-16T16:19:46 1729095586

No, GCC is right to error there, because the code uses a C++-ism (the '*' after 'auto' only makes sense in C++ but not in C).

johnisgood · 2024-10-16T14:44:01 1729089841

This difference of implementation in two of the major C compilers leaves a bad taste in my mouth. :/