inference + allocation in fix_kinds (#254)

* inference + allocation in fix_kinds

* copyto! and any in fix_kinds

Author: jishnub

src/fft.jl

@@ -563,19 +563,17 @@ function fix_kinds(region, kinds)
                 throw(ArgumentError("must supply a transform kind"))
             end
             k = Vector{Int32}(undef, length(region))
-            k[1:length(kinds)] = [kinds...]
+            copyto!(k, kinds)
             k[length(kinds)+1:end] .= kinds[end]
-            kinds = k
         end
     else
-        kinds = Int32[kinds...]
+        k = Vector{Int32}(undef, length(kinds))
+        k .= kinds
     end
-    for i = 1:length(kinds)
-        if kinds[i] < 0 || kinds[i] > 10
-            throw(ArgumentError("invalid transform kind"))
-        end
+    if any(x -> x < 0 || x > 10, k)
+        throw(ArgumentError("invalid transform kind"))
     end
-    return kinds
+    return k
 end
 
 # low-level FFTWPlan creation (for internal use in FFTW module)