eltype promotion in varmap_tp_vars (#1469)

Co-authored-by: Christopher Rackauckas <[email protected]>

Author: baggepinnen

src/variables.jl

@@ -72,20 +72,15 @@ function _varmap_to_vars(varmap::Dict, varlist; defaults=Dict(), check=false, to
     varmap = merge(defaults, varmap) # prefers the `varmap`
     varmap = Dict(toterm(value(k))=>value(varmap[k]) for k in keys(varmap))
     # resolve symbolic parameter expressions
-    example_val = nothing
     for (p, v) in pairs(varmap)
         val = varmap[p] = fixpoint_sub(v, varmap)
-        if example_val === nothing && unwrap(val) isa Number
-            example_val = val
-        end
     end
     vs = values(varmap)
     T′ = eltype(vs)
     if Base.isconcretetype(T′)
         T = T′
     else
-        example_val === nothing && throw_missingvars(varlist)
-        T = float(typeof(example_val))
+        T = foldl((t, elem)->promote_type(t, eltype(elem)), vs; init=typeof(first(vs)))
     end
     out = Vector{T}(undef, length(varlist))
     missingvars = setdiff(varlist, keys(varmap))