Just to name one: compile time code execution. It eliminates the need for a separate macro language and provides Zig zero cost generic types.
Not to mention memory leak detection, crazy fast compilation times, slices and a built in C compiler so your code can seamlessly integrate with an existing C code base (seriously no wrapper needed).
Zig is really really awesome. The only thing holding it back from mass adoption right now is that it's not finished yet, and that shows in the minimal documentation. That said, if you're comfortable tinkering, it's completely capable of production uses (and is already used in production in various companies).
This is just not true and it's the reason #1 I am not using Zig.
To give you some numbers, ZLS is a reasonably sized project (around 62k LOC of Zig) and on my very beefy machine it takes 14 seconds to build in debug mode and 78 seconds to build in release mode.
Because of the "single compilation unit" approach that Zig uses this means you are paying for that very same time regardless of where you modify your program.. so basically clean rebuild time is equal to simple modification time.
As a comparison my >100k LOC game in Rust takes less than 10s to build in release mode for modifications that happen not too far down the crate hierarchy.
So yeah, be for whatever reason you want (LLVM, no incremental builds and so on) as for today Zig is not even close to having "crazy fast compilation times".
True, current compilation times with Zig are not yet optimal. We're getting there though. As our own custom backends become complete enough we will be able to enable incremental compilation and the aim is for instant rebuilds of arbitrarily large projects.
Not to mention memory leak detection, crazy fast compilation times, slices and a built in C compiler so your code can seamlessly integrate with an existing C code base (seriously no wrapper needed).
Zig is really really awesome. The only thing holding it back from mass adoption right now is that it's not finished yet, and that shows in the minimal documentation. That said, if you're comfortable tinkering, it's completely capable of production uses (and is already used in production in various companies).