Update in anticipation of deprecating similar(f, ...) (#43)

* Update in anticipation of deprecating similar(f, ...)

Requires JuliaLang/julia#26733

* Add VERSIONing

src/OffsetArrays.jl

@@ -114,8 +114,6 @@ function Base.similar(A::AbstractArray, ::Type{T}, inds::Tuple{UnitRange,Vararg{
  OffsetArray(B, map(indexoffset, inds))
 end
 
-Base.similar(f::Function, shape::Tuple{UnitRange,Vararg{UnitRange}}) =
- OffsetArray(f(map(length, shape)), map(indexoffset, shape))
 Base.similar(::Type{T}, shape::Tuple{UnitRange,Vararg{UnitRange}}) where {T<:OffsetArray} =
  OffsetArray(T(map(length, shape)), map(indexoffset, shape))
 Base.similar(::Type{T}, shape::Tuple{UnitRange,Vararg{UnitRange}}) where {T<:Array} =
@@ -133,6 +131,24 @@ function Base.reshape(A::OffsetArray, inds::Tuple{UnitRange,Vararg{Union{UnitRan
  throw(ArgumentError("reshape must supply UnitRange axes, got $(typeof(inds)).\n Note that reshape(A, Val{N}) is not supported for OffsetArrays."))
 end
 
+if VERSION < v"0.7.0-DEV.4873"
+ # Julia PR #26733 removed similar(f, ...) in favor of just using method extension directly
+ # https://github.com/JuliaLang/julia/pull/26733
+ Base.similar(f::Function, shape::Tuple{UnitRange,Vararg{UnitRange}}) =
+ OffsetArray(f(map(length, shape)), map(indexoffset, shape))
+else
+ Base.fill(v, inds::NTuple{N, Union{Integer, AbstractUnitRange}}) where {N} =
+ fill!(OffsetArray(Array{typeof(v), N}(undef, map(indexlength, inds)), map(indexoffset, inds)), v)
+ Base.zeros(::Type{T}, inds::NTuple{N, Union{Integer, AbstractUnitRange}}) where {T, N} =
+ fill!(OffsetArray(Array{T, N}(undef, map(indexlength, inds)), map(indexoffset, inds)), zero(T))
+ Base.ones(::Type{T}, inds::NTuple{N, Union{Integer, AbstractUnitRange}}) where {T, N} =
+ fill!(OffsetArray(Array{T, N}(undef, map(indexlength, inds)), map(indexoffset, inds)), one(T))
+ Base.trues(inds::NTuple{N, Union{Integer, AbstractUnitRange}}) where {N} =
+ fill!(OffsetArray(BitArray{N}(undef, map(indexlength, inds)), map(indexoffset, inds)), true)
+ Base.falses(inds::NTuple{N, Union{Integer, AbstractUnitRange}}) where {N} =
+ fill!(OffsetArray(BitArray{N}(undef, map(indexlength, inds)), map(indexoffset, inds)), false)
+end
+
 # Don't allow bounds-checks to be removed during Julia 0.5
 @inline function Base.getindex(A::OffsetArray{T,N}, I::Vararg{Int,N}) where {T,N}
  checkbounds(A, I...)
@@ -185,6 +201,8 @@ offset(offsets::Tuple{Vararg{Int}}, inds::Tuple{}) = error("inds cannot be short
 
 indexoffset(r::AbstractRange) = first(r) - 1
 indexoffset(i::Integer) = 0
+indexlength(r::AbstractRange) = length(r)
+indexlength(i::Integer) = i
 
 macro unsafe(ex)
  esc(unsafe(ex))