Tuples in _vcat (#255)

* Tuples in _vcat

* version bump to v0.7.31

Author: jishnub

Project.toml

@@ -1,6 +1,6 @@
 name = "ApproxFunBase"
 uuid = "fbd15aa5-315a-5a7d-a8a4-24992e37be05"
-version = "0.7.30"
+version = "0.7.31"
 
 [deps]
 AbstractFFTs = "621f4979-c628-5d54-868e-fcf4e3e8185c"

src/Operators/general/InterlaceOperator.jl

@@ -451,15 +451,12 @@ operators(A::Operator) = [A]
 
 Base.vcat(A::MatrixInterlaceOperator...) =
     InterlaceOperator(vcat(map(operators,A)...))
+
+__vcat(a::VectorInterlaceOperator, b::OperatorTypes...) = (a.ops..., __vcat(b...)...)
+__vcat(a::OperatorTypes, b::OperatorTypes...) = (a, __vcat(b...)...)
+__vcat() = ()
 function _vcat(A::OperatorTypes...)
-    Av = Vector{Operator{mapreduce(eltype,promote_type,A)}}()
-    for a in A
-        if a isa VectorInterlaceOperator
-            append!(Av,a.ops)
-        else
-            push!(Av,a)
-        end
-    end
+    Av = __vcat(A...)
     InterlaceOperator(vnocat(Av...))
 end