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0 pointsCloudef11mo ago0 comments

> I do not understand your criticism of [N]. This gives compiler more information and catches errors. This is a good thing!

It only does sane thing in GCC, in other compilers it does nothing and since it's very underspec'd it's rarely used in any C projects. It's shame Dennis's fat pointers / slices proposal was not accepted.

> warrant the additional complexity IMHO

In zig case the comptime reduces complexity, because it is simply zig. It's used to implement generics, you can call zig code compile time, create and return types.

This old talk from andrew really hammers in how zig is evolution of C: https://www.youtube.com/watch?v=Gv2I7qTux7g

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uecker11mo ago

Then the right thing would be to complain about those other compilers. I agree that Dennis' fat pointer proposal was good.

Also in Zig it does not reduce complexity but adds to it by creating an distinction between compile time and run-time. It is only lower complexity by comparing to other implementations of generic which are even worse.

pron11mo ago

C also creates a distinction between compile-time and run-time, which is more arcane and complicated than that of Zig's, and your code uses it, too: macros (and other pre-processor programming). And there are other distinctions that are more subtle, such as whether the source of a target function is available to the caller's compilation unit or not, static or not etc..

C only seems cleaner and simpler if you already know it well.

uecker11mo ago

My point is not about whether compile-time programming is simpler in C or in Zig, but that is in most cases the wrong solution. My example is also not about compile time programming (and does not use macro: https://godbolt.org/z/Mc6M9dK4M), but about letting the optimizer do its job. The end result is then leaner than attempting to write a complicated compile time solution - I would argue.

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CloudefOP11mo ago

Sure there's tradeoffs for everything, but if I had to choose between macros, templates, or zig's comptime, I'd take the comptime any time.

uecker11mo ago

To each their own, I guess. I still find C to be so much cleaner than all the languages that attempt to replace it, I can not possibly see any of them as a future language for me. And it turns out that it is possible to fix issues in C if one is patient enough. Nowadays I would write this with a span type: https://godbolt.org/z/nvqf6eoK7 which is safe and gives good code.

update: clang is even a bit nicer https://godbolt.org/z/b99s1rMzh although both compile it to a constant if the other argument is known at compile time. In light of this, the Zig solution does not impress me much: https://godbolt.org/z/1dacacfzc

pjmlp11mo ago

Not only it was a good proposal, since 1990 that WG14 has not done anything else into that sense, and doesn't look like it ever will.

uecker11mo ago

Let's see. We have a relatively concrete plan to add dependent structure types to C2Y: struct foo { size_t n; char (buf)[.n]; };
Once we have this, the wide pointer could just be introduced as syntactic sugar for this. char (
buf)[:] = ..

Personally, I would want the dependent structure type first as it is more powerful and low-level with no need to decide on a new ABI.

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uecker11mo ago

Then the right thing would be to complain about those other compilers. I agree that Dennis' fat pointer proposal was good.

pron11mo ago

C only seems cleaner and simpler if you already know it well.

uecker11mo ago

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CloudefOP11mo ago

Sure there's tradeoffs for everything, but if I had to choose between macros, templates, or zig's comptime, I'd take the comptime any time.

uecker11mo ago

pjmlp11mo ago

Not only it was a good proposal, since 1990 that WG14 has not done anything else into that sense, and doesn't look like it ever will.

uecker11mo ago

Personally, I would want the dependent structure type first as it is more powerful and low-level with no need to decide on a new ABI.

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