Zig Academy · Lesson

Returning Errors from Functions

Make failure explicit in signatures.

Failure in the Signature

When a function can fail, say so in its return type. An error union like ParseError!u32 warns every caller up front.

fn parse(s: []const u8) ParseError!u32 {
    // ...
}

On the happy path you just return the payload as normal. Zig wraps that plain value into the success side of the union for you.

return 42;