revert clever axes trick now that Size is available

Co-authored-by: David Widmann <devmotion@users.noreply.github.com>

Author: mcabbott

Project.toml

@@ -7,7 +7,7 @@ StaticArraysCore = "1e83bf80-4336-4d27-bf5d-d5a4f845583c"
 
 [compat]
 StaticArrays = "1.5.7"
-StaticArraysCore = "1.3.0"
+StaticArraysCore = "1.4.0"
 julia = "1.6"
 
 [extras]

src/DiffResults.jl

@@ -1,6 +1,6 @@
 module DiffResults
 
-using StaticArraysCore: StaticArray, similar_type  #, Size  # Size is not yet in Core package
+using StaticArraysCore: StaticArray, similar_type, Size
 
 #########
 # Types #
@@ -76,8 +76,7 @@ shape information. If you want to allocate storage yourself, use the `DiffResult
 constructor instead.
 """
 JacobianResult(x::AbstractArray) = DiffResult(similar(x), similar(x, length(x), length(x)))
-# JacobianResult(x::StaticArray) = DiffResult(x, zeros(similar_type(typeof(x), Size(length(x),length(x)))))
-JacobianResult(x::StaticArray) = DiffResult(x, zeros(similar_type(typeof(x), (axes(vec(x))..., axes(vec(x))...))))
+JacobianResult(x::StaticArray) = DiffResult(x, zeros(similar_type(typeof(x), Size(length(x),length(x)))))
 
 """
     JacobianResult(y::AbstractArray, x::AbstractArray)
@@ -90,8 +89,7 @@ Like the single argument version, `y` and `x` are only used for type and
 shape information and are not stored in the returned `DiffResult`.
 """
 JacobianResult(y::AbstractArray, x::AbstractArray) = DiffResult(similar(y), similar(y, length(y), length(x)))
-# JacobianResult(y::StaticArray, x::StaticArray) = DiffResult(y, zeros(similar_type(typeof(x), Size(length(y),length(x)))))
-JacobianResult(y::StaticArray, x::StaticArray) = DiffResult(y, zeros(similar_type(typeof(x), (axes(vec(y))..., axes(vec(x))...))))
+JacobianResult(y::StaticArray, x::StaticArray) = DiffResult(y, zeros(similar_type(typeof(x), Size(length(y),length(x)))))
 
 """
     HessianResult(x::AbstractArray)
@@ -104,8 +102,7 @@ shape information. If you want to allocate storage yourself, use the `DiffResult
 constructor instead.
 """
 HessianResult(x::AbstractArray) = DiffResult(first(x), zeros(eltype(x), size(x)), similar(x, length(x), length(x)))
-# HessianResult(x::StaticArray) = DiffResult(first(x), x, zeros(similar_type(typeof(x), Size(length(x),length(x)))))
-HessianResult(x::StaticArray) = DiffResult(first(x), x, zeros(similar_type(typeof(x), (axes(vec(x))..., axes(vec(x))...))))
+HessianResult(x::StaticArray) = DiffResult(first(x), x, zeros(similar_type(typeof(x), Size(length(x),length(x)))))
 
 #############
 # Interface #