Fixed Box construction

Promotion should happen regardless of conversion to StaticArray.

Author: the-one-and-only-jackson

src/array.jl

@@ -22,18 +22,22 @@ end
 
 function Box(lower, upper; convert_to_static::Bool=false)
     @assert size(lower) == size(upper)
-    sz = size(lower)
-    continuous_lower = convert(AbstractArray{float(eltype(lower))}, lower)
-    continuous_upper = convert(AbstractArray{float(eltype(upper))}, upper)
+    T = promote_type(eltype(lower), eltype(upper)) |> float
+    continuous_lower = convert(AbstractArray{T}, lower)
+    continuous_upper = convert(AbstractArray{T}, upper)
     if convert_to_static
-        final_lower = SArray{Tuple{sz...}}(continuous_lower)
-        final_upper = SArray{Tuple{sz...}}(continuous_upper)
+        final_lower = SArray{Tuple{size(continuous_lower)...}}(continuous_lower)
+        final_upper = SArray{Tuple{size(continuous_upper)...}}(continuous_upper)
     else
-        final_lower, final_upper = promote(continuous_lower, continuous_upper)
+        final_lower, final_upper = continuous_lower, continuous_upper
     end 
     return Box{typeof(final_lower)}(final_lower, final_upper)
 end
 
+function Base.:(==)(b1::T, b2::T) where {T <: Box}
+    return (b1.lower == b2.lower) && (b1.upper == b2.upper)
+end
+
 # By default, convert builtin arrays to static
 Box(lower::Array, upper::Array) = Box(lower, upper; convert_to_static=true)
 

test/array.jl

@@ -58,6 +58,26 @@
         @test Box([1,2], [3,4]) != Box([1,3], [3,4])
     end
 
+    @testset "Box type check" begin
+        T =  [
+            BigFloat, Float64, Float32, Float16,
+            BigInt, Int128, Int64, Int32, Int16, Int8,
+            UInt128, UInt64, UInt16, UInt32, UInt8
+        ]
+        for T1 in T, T2 in T
+            x, y = [1,2], [3,4]
+            box = Box(T1.(x), T2.(y))
+            T_goal = float(promote_type(T1, T2))
+            box_goal = Box{SVector{2, T_goal}}(
+                SVector{2,T_goal}(T_goal.(x)), 
+                SVector{2,T_goal}(T_goal.(y))
+            )
+            @testset "$T1, $T2" begin
+                @test box == box_goal
+            end 
+        end
+    end
+
     @testset "Interval to box conversion" begin
         @test convert(Box, 1..2) == Box([1], [2])
     end