-Note that a ``function_ref`` object contains pointers to external memory, so
-it is not generally safe to store an instance of the class (unless you know
-that the external storage will not be freed).
-``function_ref`` is small enough that it should always be passed by value.
-
-``std::function``
-^^^^^^^^^^^^^^^^^
-
-You cannot use ``std::function`` within LLVM code, because it is not supported
-by all our target toolchains.
-
+Note that a ``function_ref`` object contains pointers to external memory, so it
+is not generally safe to store an instance of the class (unless you know that
+the external storage will not be freed). If you need this ability, consider
+using ``std::function``. ``function_ref`` is small enough that it should always
+be passed by value.