get rid of rcum_convert

Author: jw3126

base/multidimensional.jl

@@ -696,8 +696,6 @@ rcum_promote_type(op, ::Type{T}) where {T} = rcum_promote_type(op, T,T)
 # any AbstractArray here, but it's not clear how that would be possible
 rcum_promote_type(op, ::Type{Array{T,N}}) where {T,N} = Array{rcum_promote_type(op,T), N}
 
-rcum_convert(::Type{T}, x) where {T} = convert(T,x)
-rcum_convert(::Type{T}, c::Char) where {T <: AbstractString} = T(string(c))
 # accumulate_pairwise slightly slower then accumulate, but more numerically
 # stable in certain situations (e.g. sums).
 # it does double the number of operations compared to accumulate,
@@ -724,7 +722,7 @@ function accumulate_pairwise!(op::Op, result::AbstractVector, v::AbstractVector)
     n = length(li)
     n == 0 && return result
     i1 = first(li)
-    @inbounds result[i1] = v1 = v[i1]
+    @inbounds result[i1] = v1 = reduce_first(op,v[i1])
     n == 1 && return result
     _accumulate_pairwise!(op, result, v, v1, i1+1, n-1)
     return result
@@ -978,7 +976,7 @@ function accumulate!(op, B, A, dim::Integer)
         # register usage and will be slightly faster
         ind1 = inds_t[1]
         @inbounds for I in CartesianIndices(tail(inds_t))
-            tmp = rcum_convert(eltype(B), A[first(ind1), I])
+            tmp = reduce_first(op, A[first(ind1), I])
             B[first(ind1), I] = tmp
             for i_1 = first(ind1)+1:last(ind1)
                 tmp = op(tmp, A[i_1, I])
@@ -1028,7 +1026,7 @@ end
     # Copy the initial element in each 1d vector along dimension `dim`
     ii = first(ind)
     @inbounds for J in R2, I in R1
-        B[I, ii, J] = rcum_convert(eltype(B), A[I, ii, J])
+        B[I, ii, J] = reduce_first(op, A[I, ii, J])
     end
     # Accumulate
     @inbounds for J in R2, i in first(ind)+1:last(ind), I in R1
@@ -1076,7 +1074,7 @@ function _accumulate1!(op, B, v1, A::AbstractVector, dim::Integer)
     inds == linearindices(B) || throw(DimensionMismatch("linearindices of A and B don't match"))
     dim > 1 && return copyto!(B, A)
     i1 = inds[1]
-    cur_val = rcum_convert(eltype(B), v1)
+    cur_val = reduce_first(op, v1)
     B[i1] = cur_val
     @inbounds for i in inds[2:end]
         cur_val = op(cur_val, A[i])