documentation

Author: huixie90

libcxx/include/__type_traits/container_traits.h

@@ -37,6 +37,7 @@ struct __container_traits {
   // exits via an exception, the original container is unaffected
   static _LIBCPP_CONSTEXPR const bool __emplacement_has_strong_exception_safety_guarantee = false;
 
+  // A trait that tells whether a container supports `reserve(n)` member function.
   static _LIBCPP_CONSTEXPR const bool __reservable = false;
 };