Hi, I'm not sure if everyone has already noticed, that there is support for "fused types" in the recently released Cython 0.17 (http://docs.cython.org/src/userguide/fusedtypes.html). This may be extremely useful to support different dtypes without doing a explicit conversion of arrays. It's probably too early to use this feature as it is still marked as "experimental"... but we should consider to use this feature in future. Regards, Johannes