How to access arguments in 0.16 after refactor?

miagi · January 8, 2026, 11:20am

I see that there is a function initAllocator(); but it requires a variable of Args type to be passed to it. How can I create that? Is there any docu that show cases this that I might have missed?

dimdin · January 8, 2026, 11:23am

github.com/ziglang/zig

juicy main

opened 08:01PM - 19 Jul 25 UTC

closed 02:50AM - 01 Jan 26 UTC

andrewrk

enhancement standard library proposal accepted

What if you could receive a bunch of goodies in `main` simply by asking for them…? ```zig pub fn main(init: std.process.Init, args: Args) anyerror!void { ... } ``` The first arg: ```zig pub const Init = struct { /// Permanent storage for the entire process, cleaned automatically on exit. arena: *std.heap.ArenaAllocator, /// A default-selected general purpose allocator for temporary heap allocations. /// Debug mode will set up leak checking. gpa: std.mem.Allocator, /// An appropriate default Io implementation based on the target configuration. /// Debug mode will set up leak checking. io: std.Io, /// Environment variables. environ: std.process.Environ, /// Os-specific stuff. os: union { linux: Aux, windows: Peb, // ... }, }; ``` The second arg is user-defined is does that CLI pattern where you provide a type that contains already parsed CLI args, and then the start code uses type reflection to parse the args before calling main: ```zig const Args = struct { named: struct { example: u32, }, /// Memory allocated into Init.arena positional: []const []const u8, }; ``` This would be a *minimal*, opinionated parser that users would opt out of the moment they want to do something remotely sophisticated, by accepting `[]const []const u8` instead of a struct. If you think about it we already have a little bit of this with the return type - if it returns an error, start code does some opinionated stuff when an error is returned, such as print an error return trace (debug) or the error name (release) and exit(1). Users who want full control over everything can continue to use `pub fn main() noreturn {}` and have the start code do almost nothing (beyond setting up Thread Local Storage, signal handling, PIE, etc., as it already does).

miagi · January 8, 2026, 11:25am

Lovely, thank you.