Subject: [boost] [Fusion] Heterogeneous comparison rationale?
From: Louis Dionne (ldionne.2_at_[hidden])
Date: 2014-06-08 12:46:22
Dear list,
Is there a reason why Fusion does not support comparing objects of different
types? For example, the following will trigger a compilation error inside the
library because there is no operator==(int, X):
struct X { };
assert(make_vector(1, 2) != make_vector(1, X{}));
In the context of programming with heterogeneous types, one could reasonably
argue that the above should compile and pass the assertion. Of course, then
the library can't use operator== to compare objects internally, but that's
an implementation detail.
So I'm really looking for a rationale for that design decision and/or
comments from people about which way they think it should be and why.
Regards,
Louis Dionne