On this page http://dlang.org/operatoroverloading.html#Binary, is this statement:

"The expression:

a op b
is rewritten as both:

a.opBinary!("$(METACODE op)")(b)
b.opBinaryRight!("$(METACODE op)")(a)"

Which is true when a or b is object or struct, but it doesn't work for basic type or arrays wih ufcs.

I mean this:

import std.stdio;

struct S
{
    bool opBinaryRight(string op, T)(T element)
    if (op == "in")
    {
        return true;
    }
}

bool opBinary(string op, T)(T element, T[] array)
if (op == "in")
{
    return true;
}

void main(string[] args)
{
    S s;
    int a;
    int[] b;
    writeln(a.opBinary!"in"(b)); // ok
    writeln(s.opBinaryRight!"in"(a)); // ok
    writeln(a in s); // ok
    writeln(a in b); // doesn't compile
}

On 01/15/2014 07:36 PM, Daniel Kozak wrote:
> On this page http://dlang.org/operatoroverloading.html#Binary, is this
> statement:
>
> "The expression:
>
> a op b
> is rewritten as both:
>
> a.opBinary!("$(METACODE op)")(b)
> b.opBinaryRight!("$(METACODE op)")(a)"
>
> Which is true when a or b is object or struct, but it doesn't work for
> basic type or arrays wih ufcs.

It is this bug: https://d.puremagic.com/issues/show_bug.cgi?id=8062

The problem is that the spec is not explicit about this: "Operator overloading is accomplished by rewriting operators whose operands are class or struct objects into calls to specially named _member functions_."

http://dlang.org/operatoroverloading.html

Some consider it expected behaviour, based on the explicit mention of 'member function' in the spec.

On 01/15/2014 08:31 PM, Timon Gehr wrote:
>> it doesn't work for
>> basic type or arrays wih ufcs.
>
> It is this bug: https://d.puremagic.com/issues/show_bug.cgi?id=8062

Also, this enhancement: https://d.puremagic.com/issues/show_bug.cgi?id=9786