Array operations with array of structs

[anonymous via Digitalmars-d-learn]

On Monday, 6 July 2015 at 03:02:59 UTC, Nicholas Wilson wrote:
> On Monday, 6 July 2015 at 01:16:54 UTC, Peter wrote:
[...]
>> unittest{
>>     auto a = Vector3([2.0, 2.0, 0.0]);
>>     auto b = Vector3([1.0, 2.0, 1.0]);
>>     Vector3[] c = [a];
>>     Vector3[] d = [b];
>>     Vector3 e = a + b; // works
>>     Vector3[] f;
>>     f[] = c[] + d[]; // Error: invalid array operation 'f[] = 
>> c[] + d[]' because Vector3 doesn't support necessary 
>> arithmetic operations
>> }
>>
>> how can I get this to work?
>>
>> Thanks
>
> you need to define the slice operators. e.g.
>
> auto opSlice() // no parameters to get whole slice eg. a[]
>                       // can also define with opSlice(size_t i, 
> size_t j)
>                       // for access like a[ i .. j]
> {
>     return _p;
> }

`f`, `c`, and `d` are arrays though, not `Vector3`s. The code 
doesn't try to slice a Vector3. So as far as I can see, there's 
no point in adding opSlice to it.