Define `::Integer * ::FixedPoint`?

[TotalVerb]

julia> 2 * 0.5Q1f14
ERROR: InexactError()
Stacktrace:
 [1] convert at /home/fengyang/.julia/v0.6/FixedPointNumbers/src/fixed.jl:42 [inlined]
 [2] promote at ./promotion.jl:174 [inlined]
 [3] *(::Int64, ::FixedPointNumbers.Fixed{Int16,14}) at ./promotion.jl:247

This is happening because 2 is not representable in Q1f14, even though the result 1 would be. I think it is avoidable by specializing ::Integer * ::FixedPoint (and ::FixedPoint * ::Integer?) directly, but I don't have much experience with this. If this is the right thing to do, I'll make a PR.

[vchuravy]

Yes this is due to our promote rules... I think implementing ::Integer * ::FixedPoint is fine, but we need to think about whether we want to check for overflow.

[kimikage]

I misunderstood this issue. This is a problem with promotion rules only for Fixed, not for Normed. Since the birth of Normed (formerly UFixed), i.e. PR #2, it has been promoted to Float32/Float64.

I thought the checked_mul could avoid unnecessary errors, but that would lead to further inconsistencies. 😕