Forms in python don't support truediv

[Joachim Haga]

Define f.x.
  k = Constant(1.0)
and use it in a form,
  a = (1/k) * u * v * dx

This doesn't work if future.__division__ is in effect ("from __future__ import division"). In this case, __div__ is replaced by __truediv__ and __floordiv__ (or their r-equivalents). I use this mode routinely to avoid any unintended integer divisions.

So: Constant, and maybe other entities, should set __truediv__ = __div__ and __rtruediv__ = __rdiv__.

(I believe Constant's __div__ semantics are really __truediv__ semantics anyway.)

[Anders Logg (logg)]

Looks like this belongs in UFL