Versioning for Thrift, remove thrift/lib/cpp/config.h

[folly.git] / folly / ApplyTuple.h

diff --git a/folly/ApplyTuple.h b/folly/ApplyTuple.h
index 3fe30c3d1b996c04c9de8f0d210e89e3828b25f7..6fe6093d5a4ccdd8c34fe32af77405ee7d161889 100644 (file)
--- a/folly/ApplyTuple.h
+++ b/folly/ApplyTuple.h
@@ -51,13 +51,24 @@ struct DerefSize
   : std::tuple_size<typename std::remove_reference<Tuple>::type>
 {};
 
+template<class Tuple, class ...Unpacked> struct ExprDoUnpack {
+  enum {
+    value = sizeof...(Unpacked) < DerefSize<Tuple>::value
+  };
+};
+
+template<class Tuple, class ...Unpacked> struct ExprIsUnpacked {
+  enum {
+    value = sizeof...(Unpacked) == DerefSize<Tuple>::value
+  };
+};
+
 // CallTuple recursively unpacks tuple arguments so we can forward
 // them into the function.
 template<class Ret>
 struct CallTuple {
   template<class F, class Tuple, class ...Unpacked>
-  static typename std::enable_if<
-    (sizeof...(Unpacked) < DerefSize<Tuple>::value),
+  static typename std::enable_if<ExprDoUnpack<Tuple, Unpacked...>::value,
     Ret
   >::type call(const F& f, Tuple&& t, Unpacked&&... unp) {
     typedef typename std::tuple_element<
@@ -71,8 +82,7 @@ struct CallTuple {
   }
 
   template<class F, class Tuple, class ...Unpacked>
-  static typename std::enable_if<
-    (sizeof...(Unpacked) == DerefSize<Tuple>::value),
+  static typename std::enable_if<ExprIsUnpacked<Tuple, Unpacked...>::value,
     Ret
   >::type call(const F& f, Tuple&& t, Unpacked&&... unp) {
     return makeCallable(f)(std::forward<Unpacked>(unp)...);