From: "michael toksvig" <michaeltoksvig@yahoo.com>
matt, i don't think your code example disambiguates what rob and i are disagreeing on
when you say:
MyCv c = a + b; // Should fail
you don't say why you think it should fail. there are (at least) 3 possibilities: a) at compile time (because it is an error to try to assign a 0-20 number to a 0-10 number) b) at runtime, during the assignment (because it is an error to assign a 0-20 number to a 0-10 number if it is outside the 0-10 range) c) at runtime, during the addition (because it is an error to add two 0-10 numbers if they add up to more than 10)
i think a) and b) are both useful, and i think rob is advocating c)
Yes, but using a checking policy, you can have all three, though I'm not sure how to express the difference between a) and c). "compile_time_check" and "run_time_check" are insufficient. You might need separate policies to dictate how conversions and operations are checked. -- Rob Stewart stewart@sig.com Software Engineer http://www.sig.com Susquehanna International Group, LLP using std::disclaimer;