Re: Implicit conversion from 'Ok' to 'Result' type when returning functions

[Nicholas Wilson via Digitalmars-d-learn]

On Sunday, 21 May 2017 at 09:29:40 UTC, David  Zhang wrote:
On Sunday, 21 May 2017 at 09:15:56 UTC, Nicholas Wilson wrote:
have free functions
 Result!(T, ErrorEnum) ok(T)(T t) { return Result(t); }
 Result!(T, ErrorEnum) error(T)(ErrorEnum e) { return 
Result(e); }

then go

if (!foo)
    return ok(42);
else
    return error(Error.fooHappened);

Ah, I think you misread. ErrorEnum is a template type, like 
`T`. There's no ErrorEnum enum specified.

Well then it becomes
 Result!(T, E) ok(T,E)     (T t) { return Result(t); }
 Result!(T, E) error(T,E)(E e) { return Result(e); }

and then provided it can be inferred (e.g. from the function 
signature)
it will still work.