No support for `IntExpressions`

[cprudhom]

https://choco-solver.org/docs/modeling/intexpressions/

[dimitri-justeau]

Actually, in https://github.com/chocoteam/pychoco/blob/master/pychoco/variables/intvar.py , such expression are implemented through operator overloading, e.g.:

m = Model()
a = m.intvar(0, 10)
b = m.intvar(0, 10)
c = a + b

cwill be an intvar equals to a + b.

Specifically, the following operators are overloaded:

+ - (sub and neg) * / ** (pow) % (mod) == (reifies an equal arithmetic constraint), != (idem), <=, >=, <, >

Though, I did not directly rely on the IntExpression Api to do this, but rather on views and posting constraints. You'll tell me if it is okay or not.