use concrete type constructors at critical places

base/multidimensional.jl

@@ -65,15 +65,17 @@ end
 for op in (:+, :-, :min, :max)
  @eval begin
  stagedfunction ($op){N}(index1::CartesianIndex{N}, index2::CartesianIndex{N})
+ I = index1
  args = [:($($op)(index1[$d],index2[$d])) for d = 1:N]
- :(CartesianIndex{$N}($(args...)))
+ :($I($(args...)))
  end
  end
 end
 
 stagedfunction *{N}(a::Integer, index::CartesianIndex{N})
+ I = index
  args = [:(a*index[$d]) for d = 1:N]
- :(CartesianIndex{$N}($(args...)))
+ :($I($(args...)))
 end
 *(index::CartesianIndex,a::Integer)=*(a,index)
 
@@ -107,13 +109,14 @@ done(R::StepRange, state::(Bool, CartesianIndex{1})) = state[1]
 done(R::UnitRange, state::(Bool, CartesianIndex{1})) = state[1]
 
 stagedfunction next{T,N}(A::AbstractArray{T,N}, state::(Bool, CartesianIndex{N}))
+ I = state[2]
  finishedex = (N==0 ? true : :(newindex[$N] > size(A, $N)))
  meta = Expr(:meta, :inline)
  quote
  $meta
  index=state[2]
  @inbounds v = A[index]
- newindex=@nif $N d->(index[d] < size(A, d)) d->@ncall($N, CartesianIndex{$N}, k->(k>d ? index[k] : k==d ? index[k]+1 : 1))
+ newindex=@nif $N d->(index[d] < size(A, d)) d->@ncall($N, $I, k->(k>d ? index[k] : k==d ? index[k]+1 : 1))
  finished=$finishedex
  v, (finished,newindex)
  end
@@ -125,7 +128,7 @@ stagedfunction next{I<:CartesianIndex}(iter::CartesianRange{I}, state::(Bool, I)
  quote
  $meta
  index=state[2]
- newindex=@nif $N d->(index[d] < iter.stop[d]) d->@ncall($N, CartesianIndex{$N}, k->(k>d ? index[k] : k==d ? index[k]+1 : iter.start[k]))
+ newindex=@nif $N d->(index[d] < iter.stop[d]) d->@ncall($N, $I, k->(k>d ? index[k] : k==d ? index[k]+1 : iter.start[k]))
  finished=$finishedex
  index, (finished,newindex)
  end