From d7ff02e043b872249b4208ec5d6219a57af31479 Mon Sep 17 00:00:00 2001
From: Martin Holters <martin.holters@hsu-hh.de>
Date: Mon, 23 Jan 2017 08:45:43 +0100
Subject: [PATCH 1/4] Add `setindex` for tuples

---
 base/tuple.jl | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/base/tuple.jl b/base/tuple.jl
index 05fdd8bd256a6..6e6add6675e2d 100644
--- a/base/tuple.jl
+++ b/base/tuple.jl
@@ -18,6 +18,14 @@ getindex(t::Tuple, i::Real) = getfield(t, convert(Int, i))
 getindex{T}(t::Tuple, r::AbstractArray{T,1}) = tuple([t[ri] for ri in r]...)
 getindex(t::Tuple, b::AbstractArray{Bool,1}) = length(b) == length(t) ? getindex(t,find(b)) : throw(BoundsError(t, b))
 
+# returns new tuple; N.B.: becomes no-op if i is out-of-bounds
+setindex(x::Tuple, v, i::Integer) = _setindex((), x, v, i::Integer)
+function _setindex(y::Tuple, r::Tuple, v, i::Integer)
+    @_inline_meta
+    _setindex((y..., ifelse(length(y) + 1 == i, v, first(r))), tail(r), v, i)
+end
+_setindex(y::Tuple, r::Tuple{}, v, i::Integer) = y
+
 ## iterating ##
 
 start(t::Tuple) = 1

From e36e14e7716da402281199ca7e54ea74de25fa4e Mon Sep 17 00:00:00 2001
From: Martin Holters <martin.holters@hsu-hh.de>
Date: Mon, 23 Jan 2017 13:17:03 +0100
Subject: [PATCH 2/4] Improve inferability of `slicedim`

---
 base/abstractarraymath.jl | 2 +-
 test/arrayops.jl          | 1 +
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/base/abstractarraymath.jl b/base/abstractarraymath.jl
index 72eba80cfa3b1..2c6d79e657016 100644
--- a/base/abstractarraymath.jl
+++ b/base/abstractarraymath.jl
@@ -113,7 +113,7 @@ function slicedim(A::AbstractArray, d::Integer, i)
     d >= 1 || throw(ArgumentError("dimension must be ≥ 1"))
     nd = ndims(A)
     d > nd && (i == 1 || throw_boundserror(A, (ntuple(k->Colon(),nd)..., ntuple(k->1,d-1-nd)..., i)))
-    A[( n==d ? i : indices(A,n) for n in 1:nd )...]
+    A[setindex(indices(A), i, d)...]
 end
 
 function flipdim(A::AbstractVector, d::Integer)
diff --git a/test/arrayops.jl b/test/arrayops.jl
index f1070b925ebac..2ee397f82d0d7 100644
--- a/test/arrayops.jl
+++ b/test/arrayops.jl
@@ -1608,6 +1608,7 @@ B = 1.5:5.5
         @test_throws ArgumentError slicedim(A,0,1)
         @test slicedim(A, 3, 1) == A
         @test_throws BoundsError slicedim(A, 3, 2)
+        @test @inferred(slicedim(A, 1, 2:2)) == collect(2:4:20)'
     end
 end
 

From 9a95c65f4a47f1c796fb04f2598666c441bdbfff Mon Sep 17 00:00:00 2001
From: Martin Holters <martin.holters@hsu-hh.de>
Date: Tue, 24 Jan 2017 13:24:20 +0100
Subject: [PATCH 3/4] Remove `slicedim` specialization for `BitArray`

---
 base/bitarray.jl | 31 -------------------------------
 1 file changed, 31 deletions(-)

diff --git a/base/bitarray.jl b/base/bitarray.jl
index 1a0c6b4940a89..42cac47fd5d67 100644
--- a/base/bitarray.jl
+++ b/base/bitarray.jl
@@ -1280,37 +1280,6 @@ end
 
 # TODO some of this could be optimized
 
-function slicedim(A::BitArray, d::Integer, i::Integer)
-    d_in = size(A)
-    leading = d_in[1:(d-1)]
-    d_out = tuple(leading..., d_in[(d+1):end]...)
-
-    M = prod(leading)
-    N = length(A)
-    stride = M * d_in[d]
-
-    B = BitArray(d_out)
-    index_offset = 1 + (i-1)*M
-
-    l = 1
-
-    if M == 1
-        for j = 0:stride:(N-stride)
-            B[l] = A[j + index_offset]
-            l += 1
-        end
-    else
-        for j = 0:stride:(N-stride)
-            offs = j + index_offset
-            for k = 0:(M-1)
-                B[l] = A[offs + k]
-                l += 1
-            end
-        end
-    end
-    return B
-end
-
 function flipdim(A::BitArray, d::Integer)
     nd = ndims(A)
     1 ≤ d ≤ nd || throw(ArgumentError("dimension $d is not 1 ≤ $d ≤ $nd"))

From 8f9a62ee74f9c9693b2a8492e4f3c40ccca1addc Mon Sep 17 00:00:00 2001
From: Martin Holters <martin.holters@hsu-hh.de>
Date: Wed, 25 Jan 2017 14:42:57 +0100
Subject: [PATCH 4/4] Add `slicedim(::BitVector, ::Integer, ::Integer)` to
 restore previous behavior

---
 base/bitarray.jl | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/base/bitarray.jl b/base/bitarray.jl
index 42cac47fd5d67..b908a20d12001 100644
--- a/base/bitarray.jl
+++ b/base/bitarray.jl
@@ -1278,6 +1278,18 @@ end
 
 ## Data movement ##
 
+# preserve some special behavior
+function slicedim(A::BitVector, d::Integer, i::Integer)
+    d >= 1 || throw(ArgumentError("dimension must be ≥ 1"))
+    if d > 1
+        i == 1 || throw_boundserror(A, (:, ntuple(k->1,d-2)..., i))
+        A[:]
+    else
+        fill!(BitArray{0}(), A[i]) # generic slicedim would return A[i] here
+    end
+end
+
+
 # TODO some of this could be optimized
 
 function flipdim(A::BitArray, d::Integer)