comptime type deduction

[bheads]

It seems like this might become a common pattern for generic coding in zig

pub fn foo(comptime T: type, T: a) void {
}

var a  = 5;
foo(int, a); 

In these cases the compiler knows the type of a, it would be useful if you did not have to supply the type.

foo(a);  //<< much simpler and cleaner

Maybe some reorganization of the function signature.

pub fn foo(T: a, comptime T: type = @typeOf(a)) void  {..}

[andrewrk]

have you seen this yet?

fn foo(a: var) void {
}

test "aoeu" {
    var a: u32  = 5;
    foo(a); 
}

[bheads]

I have not seen that yet, should cover a lot of cases. But what about enforcing same types

pub fn foo(comptime T: type, a : T, b : T)

Would have to include a typeof check in the body

[andrewrk]

That can work like this:

fn foo(a: var, b: @typeOf(a)) void {}

However perhaps you want to resolve the types with peer type resolution. There's an open issue for that: #439

[bheads]

Good to know typeOf works likes this. Thanks.