Hi &rzej, Thanks for all the comments, very helpful. I think passing the reporting method to the check makes sense and helps having uniformity at the interface level. Something I'm wondering is if safe_float should receive only 1 policy (that could be composed, this is what I have implemented now) or if I should use variadic template and allow to pass multiple pass as many policies as wanted and make their composition internally. Something like: safe_float<typename FP, class P, class... Ps>; vs safe_float<typename FP, class P> I'm also implementing a convenience.hpp with compositions of policies that may be common to mix, for example, I define both_flows as the check of both underflow and overflows. About division by zero. The following code compiles with no warning in clang (-wall -pedatic). float a = 1.0f; float b = numeric_limits::max(); float c = a/b; float d = c/b; float e = a/d; I'm not sure if there is any static analyzer that will catch that the flag of div_by_zero is on after last operation, and probably there is even less chance that this is catched if d and e are in different cpp files or one is coming from user input as cin. Do you know about such a tool that will catch things like this? About the casts, I'm including cast policies for casts too, I calling them allow_cast_from<T> and allow_cast_to<T>, by default they don't mix with other types. Silently casting to other types is a big source of errors when using float. I'm also including _sf, _sd _sld literal suffixes. Best regards, Damian