UFCS for struct opCall?

[bearophile]

On request by Maxim Fomin I ask an opinion here. This is a very 
small enhancement request, that for me is borderline bug report 
(so originally I didn't plan in showing it in the main D 
newsgroup):

http://d.puremagic.com/issues/show_bug.cgi?id=9857



Maybe this should be valid:


struct Foo {
     int opCall(bool b) {
         return 0;
     }
}
void main() {
    Foo foo;
    auto b1 = foo(true); // OK
    auto b2 = true.foo;  // Error
}


dmd 2.063alpha gives:

temp.d(9): Error: no property 'foo' for type 'bool'


Explanation:

1) I am using UFCS often in D, for functions, higher order 
functions, etc. A struct with an opCall method is usable like a 
function with state. So for uniformity with the other functions 
I'd like to use it with UFCS. When you have a long UFCS chain you 
don't want to break it, if it's possible.


2) Both struct constructors, struct implicit constructors and 
struct static opCall support UFCS, so I don't see a good reason 
for just the normal struct opCall to not support it:


struct Foo {
     static int opCall(int x) {
         return x * 2;
     }
}
struct Bar {
     int x;
     this(int y) {
         x = y * 2;
     }
}
struct Spam {
     int x;
}
void main() {
     assert(10.Foo == 20);
     assert(10.Bar.x == 20);
     assert(10.Spam.x == 10);
}


Jonathan Davis doesn't like this. For more information I suggest 
to take a look at the thread in Bugzilla.

- - - - - - - - - - -

Regarding UFCS, currently this doesn't work, I don't know if this 
should be considered a bug or not (I think the answer is 
positive):


struct Node {}
void foo(Node* p) {}
void main() {
     auto p = new Node();
     foo(p); // OK
     p.foo;  // Error: no property 'foo' for type 'Node'
}


Bye,
bearophile