Again not publicly documented because I don't like the naming and I
don't have the full behavior and interactions figured out yet -- i.e.,
an array of VertexFormats would be printed with Debug::packed as a long
string of characters without any whitespace. Not good, thus this
feature probably needs to be split in two, with this being named
"compact" or something else.
It's dangerous, as in case of failure it will attempt to print them as
strings. Plus now with latest de-std-string-ification of TestSuite it
causes the compilation to fail due to an ambigupus overload.
This should eventually be catched and disallowed directly by the Tester
class.
This is in line with how the other APIs are named (for example
ObjectDataXD have instance type and instance). This would be very hard
to change later without breaking backwards compatibility, so I'm doing
it now, until the animation APIs get widely used.
This reduces the templated code a bit, as I moved the index assertion to
the *.cpp file. Also the function now returns a reference to avoid
needless copies -- it's a view, but still quite a heavy view.