I see it this way, the full signature for defining a variable is:

    var foo: Foo = Foo{};

There's two ways to shorten it:

    var foo = Foo{};
    var foo: Foo = .{};

It can infer the type of the var from the right hand side; or the type of the right side from the type of the var.

So when you see .{} as an argument, it is inferring the type from the function signature. It happens to be empty only because it's using default values (or is a tuple with 0 items).

Edit: fixed the extra dots.

▲ dnautics 2 hours ago | parent [-]

that's not quite right.

1) It's var foo = Foo{...}; (no intervening dot)

2) I think parent commenter is referring to function call use case call_my_func(.{...})

▲

hiccuphippo 2 hours ago | parent [-]

1) Ah yes, just typing from memory. Point still stands.

2) Adressed in the last paragraph.

	▲	dnautics 2 hours ago \| parent [-]
		Point being, these two things aren't different (variable assignment and function calls); IIUC they go through the same analysis pathway, result location semantics. https://ziglang.org/documentation/master/#Result-Location-Se... It's a little bit weird, since the types flow in the reverse direction than you would expect.