EntityQueryBuilder.ForEach is not compiling with two ComponentData and one BufferElementData

Question

I'm using the Unity Entity Component System. When I try to write the following code:

Entities.WithAll<SomeComponentData, SomeComponentData2, SomeBufferElementData>()
        .ForEach((Entity entity,  ref SomeComponentData componentData, ref SomeComponentData2 componentData2, DynamicBuffer<SomeBufferElementData> buffer) => {

});

I get the following error error CS0315: The type 'Unity.Entities.Entity' cannot be used as type parameter 'T0' in the generic type or method 'EntityQueryBuilder.ForEach<T0>(EntityQueryBuilder.F_D<T0>)'. There is no boxing conversion from 'Unity.Entities.Entity' to 'Unity.Entities.IComponentData'.

It compiled fine when I was just using one ComponentData and one BufferElementData i.e. the following worked:

Entities.WithAll<SomeComponentData, SomeBufferElementData>()
        .ForEach((Entity entity,  ref SomeComponentData componentData, DynamicBuffer<SomeBufferElementData> buffer) => {

});

I had a look at the ForEach code, which is generated code with lots of permutations of components and dynamicbuffers, but I couldn't find this one. (see answer - I just wasn't looking hard enough!) What happens in this situation where the permutation of ComponentData and BufferElementData is not supported?

Answer 1

Turns out this permutation was supported but I had to put the DynamicBuffer first. That is:

Entities.WithAll<SomeBufferElementData, SomeComponentData, SomeComponentData2>()
        .ForEach((Entity entity,  DynamicBuffer<SomeBufferElementData> buffer, ref SomeComponentData componentData, ref SomeComponentData2 componentData2) => {

});

I found this out by looking at the IJobForEachWithEntity_XXX interfaces. I found that there was an IJobForEachWithEntity_EBCC interface, which tipped me off to the fact that the buffer had to go before the components.

Hope this will save someone a few hours of their time!