On 11/02/2013 03:41 PM, TheFlyingFiddle wrote:
> The problem i am faced with is that i need a way to figure out the
> return value of opDispatch by the invokation call.
If I now understand you correctly, what initially confused my was
"invocation call." Because "invocation" makes me think about the actual
arguments of the functino call.
> all the information i need is here
>
> int a = foo.baz("hello");
>
> This gives returntype int.
So, what you are trying to do is to get the return type from the
left-hand side of the assignment operator.
> So is there a way to gain this information in opDspatch?
I don't think so. You can always return a special (similar to Variant
that you mentioned) and play with automatic type conversions no that type.
> Is it possible to do something like this?
>
> auto a = foo.baz!(int)("hello");
Hmmm. I don't think so. "baz" itself becomes the first argument of
opDispatch. So I tried the following ugly thing but it does not work either:
import std.stdio;
struct S
{
R opDispatch(string name, R, T...)(T parameters)
{
return R.init;
}
}
void main()
{
auto s = S();
auto r0 = s.foo!("foo", int)("hello"); // does not compile
auto r1 = s.bar!("bar", double)(100);
static assert (is (typeof(r0) == int));
static assert (is (typeof(r1) == double));
}
Ali
