Merge pull request JuliaLang#26217 from JuliaLang/kf/bitsetperf

Special case BitSet union! (fix performance)
tekverkp · Feb 27, 2018 · 6b5755c · 6b5755c
2 parents d0723bf + c5b26db
commit 6b5755c
Showing 1 changed file with 3 additions and 0 deletions.
diff --git a/base/bitset.jl b/base/bitset.jl
@@ -28,6 +28,9 @@ very large integers), use [`Set`](@ref) instead.
 """
 BitSet(itr) = union!(BitSet(), itr)
 
+# Special implementation for BitSet, which lacks a fast `length` method.
+union!(s::BitSet, itr) = foldl(push!, s, itr)
+
 @inline intoffset(s::BitSet) = s.offset << 6
 
 eltype(::Type{BitSet}) = Int