Originally those were assertions that were kept even in release builds,
which meant that calling math.angle() on non-normalized vectors aborted
the whole Python interpreted. Not great. But then the assertions were
made debug-only, which means invalid usage from Python (where the
bindings are usually only built as Release) now silently gives back a
wrong result, which is perhaps even worse.
Because the Python overhead is already massive due to all string lookup
and such, doing one more check in the implementations isn't really going
to slow down anything. Thus I'm mirroring all (debug-only) Magnum
assertions on the Python side, turning them into exceptions. With proper
messages as well, because those are extremely useful.
Vladimír Vondruš
7a35f405b4