Instead of saying "which is not supported" in each assert, which is
vague and might imply that "it eventually will be supported", document
the actual reason in a single place, which is the MeshAttributeData docs.
This allows people to directly pass Containers::Array<Trade::MeshData>
there, without having to put them to an annoying temporary
Containers::Array<Containers::Reference<const Trade::MeshData>.
The Iterable header is included for backwards compatibility, apart from
that there should be no breaking change.
The array size is always last, defaulting to 0. This makes it consistent
with the offset-only constructor and removes two unnecessary overloads.
It's a breaking change, but I don't think array attributes have many
users yet -- and better to do this now than later. In any case, sorry
about breaking your code.
Until now, except for an attribute-less index-less mesh, the vertex
count was only implicitly taken from passed attributes, but it was
severely limiting:
- There was no way to set vertex count for an attribute-less
indexed mesh, which didn't make sense
- All code that made non-owning MeshData instances referencing another
MeshData had to explicitly handle the attribute-less corner case to
avoid vertex count getting lost
- Offset-only attributes couldn't be used to specify static layout of
meshes with dynamic vertex count, causing unnecessary extra
allocations especially in the Primitives library.