make hypercube more generic + bug fix

Author: maltezfaria

src/Geometry/referenceshapes.jl

@@ -72,19 +72,18 @@ the lower corner at the origin and the upper-corner at `(1,1,…,1)`.
 """
 struct ReferenceHyperCube{N} <: AbstractReferenceShape{N}
 end
+Base.in(x,::ReferenceHyperCube)    = all(0 ≤ xi ≤ 1 for xi in x)
 
+center(::SType{ReferenceHyperCube{N}}) where {N} = svector(i->0.5,N)
+
+number_of_nodes(::SType{ReferenceHyperCube{N}}) where {N} = 2^N
 
 """
     const ReferenceSquare = ReferenceHyperCube{2}
 
 Singleton type representing the square with vertices `(0,0),(0,1),(1,1),(1,0)`
 """
 const ReferenceSquare = ReferenceHyperCube{2}
-Base.in(x,::ReferenceSquare)    = 0 ≤ x[1] ≤ 1 && 0 ≤ x[2] ≤ 1
-center(::Type{ReferenceSquare}) = SVector(0.5,0.5)
-center(::ReferenceSquare)       = SVector(0.5,0.5)
-number_of_nodes(::Type{ReferenceSquare}) = 4
-number_of_nodes(::ReferenceSquare)       = 4
 
 vertices(sq::ReferenceSquare) = SVector(0,0), SVector(1,0), SVector(1,1), SVector(0,1)
 

src/Interpolation/hyperrectangle.jl

@@ -200,6 +200,7 @@ function HyperRectangle(els,cube=false)
         ub = max.(xc .+ w/2,ub)
         # TODO: return HyperCube instead
     end
+    lb == ub && (lb = prevfloat.(lb); ub = nextfloat.(ub)) # to avoid "empty" rectangles
     return HyperRectangle(lb,ub)
 end