The following gives:
"Error: 'a += b' is not a scalar, it is a C"
although UFCS should engage.

-manfred

class C{}
int main(){
  void opOpAssign( string op)( C a, C b){
  }
  C a, b;
  a+= b;
}

On 05/15/2015 11:31 PM, Manfred Nowak wrote:
> class C{}
> int main(){
>    void opOpAssign( string op)( C a, C b){
>    }
>    C a, b;
>    a+= b;
> }

https://issues.dlang.org/show_bug.cgi?id=8062

On Friday, May 15, 2015 21:31:35 Manfred Nowak via Digitalmars-d-learn wrote:
> The following gives:
> "Error: 'a += b' is not a scalar, it is a C"
> although UFCS should engage.
>
> -manfred
>
> class C{}
> int main(){
>   void opOpAssign( string op)( C a, C b){
>   }
>   C a, b;
>   a+= b;
> }

Overloaded operators have to be defined as part of the type that they're overloading the operator for, and UFCS is only ever used with the . syntax. So, this isn't a bug.

- Jonathan M Davis

Jonathan M Davis wrote:

> UFCS is only ever used with the . syntax

The docs say so. Thx.

-manfred

On Saturday, 16 May 2015 at 05:56:26 UTC, Jonathan M Davis wrote:
> On Friday, May 15, 2015 21:31:35 Manfred Nowak via Digitalmars-d-learn wrote:
>> The following gives:
>> "Error: 'a += b' is not a scalar, it is a C"
>> although UFCS should engage.
>>
>> -manfred
>>
>> class C{}
>> int main(){
>>   void opOpAssign( string op)( C a, C b){
>>   }
>>   C a, b;
>>   a+= b;
>> }
>
> Overloaded operators have to be defined as part of the type that they're
> overloading the operator for, and UFCS is only ever used with the . syntax.
> So, this isn't a bug.

Besides, UFCS doesn't work with local functions either; `opOpAssign()` would need to be moved out of `main()`.