Type inference difference in `mapreduce(f, op, t)` vs `reduce(op, map(f, t))`

General Usage Performance
,
1

For tuples, it seems mapreduce has poorer type inference than map + reduce.

julia> using FillArrays, Infinities, InfiniteArrays, Test

julia> ax = Ones{Int}(InfiniteCardinal{0}());

julia> y = (ax,ax);

julia> @inferred (t -> mapreduce(sum, *, t))(y)
ERROR: return type InfiniteCardinal{0} does not match inferred return type Any
Stacktrace:
 [1] error(s::String)
   @ Base ./error.jl:35
 [2] top-level scope
   @ REPL[6]:1

julia> @inferred (t -> reduce(*, map(sum, t)))(y)
ℵ₀

This is perhaps because map is specialized for tuples. Is this an instance where code_warntype isn’t accurate, and the result is correctly inferred in both cases? Or is it better to replace mapreduce by map + reduce?