Handling different types gracefully

[Roderick Gibson]

On Monday, 1 July 2013 at 12:16:50 UTC, bearophile wrote:
> Roderick Gibson:
>
>> auto entities = new Entities();
>> auto entity_id = entities.createEntity();
>> entities.addComponent!(position)(entity_id, pos);
>> entities.addComponent!(movement)(entity_id, mov);
>> entities.addComponent!(collision)(entity_id, col);
>> auto physics_data = 
>> entities.getEntitiesWithComponents!(position, movement, 
>> collision)();
>>
>> The two big requirements are some kind of regular, queryable 
>> structure to hold the components (of different types), and the 
>> ability to filter by type. Is anything like that remotely 
>> possible?
>
> If the possible types are know, then there's 
> std.variant.Algebraic, otherwise there is a free Variant or 
> VariantN. They are not perfect, but maybe they are good enough 
> for you.
>
> Bye,
> bearophile

Variant is a possiblity. How is the performance with large 
containers of these, since these structures will likely hold the 
majority of the data in the game?

> Waiting for multiple "alias this" ??
> And opDispatch to respond to unimplemented components.

I'm not sure what you mean by this.