Support binary operations between different complex types

[aguinet]

For instance, support std::comple + std::complex by
casting the first operand to a std::complex.

[serge-sans-paille]

looks ok to me, just waiting for a few test cases :-)

Also, https://travis-ci.org/serge-sans-paille/pythran/jobs/169716049 is not passing because you should run clang-format-3.6 on the c++ files

[aguinet]

Branch rebased on master with clang-format applied on complex.hpp :) !

[serge-sans-paille]

@aguinet due to a (new) limitation of Travis, this PR cannot be autoamtically validated #627 solves this issue, you'll need to rebase on it once it's merged by @pbrunet

[serge-sans-paille]

ISTM the operator already exists when T == U... how do you handle the conflict?

Without a test, it's hard to tell if this work, please add a few in pythran/tests/test_complex.py

[aguinet]

Hmmm indeed, gonna check that!

[aguinet]

I repushed the branch with two tests added. It checks whether the operator + works with both operands the same type and different type. Both tests works. My understanding is that, as the operator+ is well-defined for std::complex, it doesn't try the templated version.

[serge-sans-paille]

ok. LGTM if travis is ok too.

[serge-sans-paille]

@aguinet you can rebase now.

[aguinet]

Rebase done, go travis go! :)