binary expression...

[captain_fid via Digitalmars-d-learn]

On Saturday, 21 May 2016 at 18:33:53 UTC, Anonymouse wrote:
> On Saturday, 21 May 2016 at 18:10:55 UTC, captain_fid wrote:
>> Please forgive if asked before. My google skills seemed to 
>> fail me and didn't see any result from search.
>>
>> My problem is simple (though not my understanding LOL).
>>
>> struct D {
>>       int value;
>>       bool opEquals()(bool value) const { return (value == 
>> value); }
>> }
>>
>> D aD;
>> if (aD == 1) { // OK
>> }
>>
>> if (aD) {      //  Error: expression aD of type D does not 
>> have a boolean value
>> }
>>
>> Is there a way to overload for this? What am I missing?
>
> struct D
> {
>     int value;
>
>     bool opEquals(T)(T value) const {
>         return value == this.value;
>     }
>
>     bool opCast(T : bool)() const {
>         return this != this.init;  // or some such
>     }
> }
>
> Not tested, written on my phone so might have missed something.

Perfect.. and your 'phoned-in' coding is impressive.

opCast is the biggest thing I was 
missing/forgetting/misunderstanding here.

I Still need to look back at what is happening with vit's 
solution.

Sorry again for the bad example to both of you.