A type system in programming languages is a way to express and enforce compile time constraints (conventionally, anyway).
zig's type system is pretty straightforward, but its comptime is very powerful and, among other things, can enforce arbitrary compile time constraints. It's not the same as rust's types, but I wonder if it isn't better in many ways.
It's not comparable, comptime is more of an alternative to macros. You can build complex systems with it, but they don't natively give you the algebraic reasoning abilities that the typechecker does, at best you'd have to reimplement it yourself in an ad hoc way. Rust's proc macros are also fully programmable and have comparable expressive power to comptime.
I used Zig in the past (after my "why don't we just write everything simply in C" phase). I don't think I used comptime too much, but I understood why it would be useful.
Now I write Rust and absolutely love it, except for the damn macro edge cases, like not being able to use a known-at-compile-time string for format!() unless it's a literal (I even tried to fake it with more macros, no dice). I think Zig's Andrew Kelley mentioned this exact scenario, if I recall correctly.
It's funny because I do write a lot of code that generates code, but I avoid macros if I can.
zig's type system is pretty straightforward, but its comptime is very powerful and, among other things, can enforce arbitrary compile time constraints. It's not the same as rust's types, but I wonder if it isn't better in many ways.