Use if-else instead of dispatch

src/base.jl

@@ -3,11 +3,13 @@
 # Use recursion to avoid inference bail-out in `map`
 #adapt_structure(to, xs::Union{Tuple,NamedTuple}) = map(adapt(to), xs)
 adapt_structure(to, xs::NamedTuple) = map(adapt(to), xs)
-adapt_structure(to, xs::Tuple) = map(adapt(to), xs)
-adapt_structure(to, xs::NTuple{N}) where {N} = map(adapt(to), xs)
 # Specialize on small Tuples
-for N in 1:10
-  @eval adapt_structure(to, xs::NTuple{$N}) = _adapt_tuple_structure(to, xs)
+function adapt_structure(to, xs::Tuple)
+  if length(xs) ≤ 20
+    _adapt_tuple_structure(to, xs)
+  else
+    map(adapt(to), xs)
+  end
 end
 _adapt_tuple_structure(to, xs::Tuple) =
   (adapt(to, first(xs)), _adapt_tuple_structure(to, Base.tail(xs))...)