Re: Get operator overloads

[via Digitalmars-d-learn]

On Tuesday, 2 September 2014 at 18:55:50 UTC, Ivan Timokhin wrote:
Is it possible to get all overloads of an operator for a 
particular type?

I.e., having this struct definition, is it possible to tell at 
compile time that it can be added with double and int[]?

struct S
{
    void opBinary(string op : "+")(double);
    void opBinary(string op : "+")(int[]);
}

To clarify, I am well aware that it can also be overloaded 
through the second argument via opBinaryRight, but for now I'm 
only interested in overloads provided by S itself.

I've tried __traits(getOverloads), but with no success: 
__traits(getOverloads, S, "opBinary") returns empty tuple,
and __traits(getOverloads, S, `opBinary!"+"`) results in a 
compilation
error (dmd 2.065):

Error: no property 'opBinary!"+"' for type 'S'
Error: (S).opBinary!"+" cannot be resolved

I can't answer the question about inspecting the overloads, but 
if you just want to know whether it supports addition, the 
idiomatic way is to test whether it compiles:

    enum supportsAddition(S) = is(typeof(S.init + 0.0));

    static if(supportsAddition!MyType) { ... }