codefuncode
diff --git a/‎docs/standard-library/basic-filebuf-class.md‎
Lines changed: 3 additions & 1 deletion b/‎docs/standard-library/basic-filebuf-class.md‎
Lines changed: 3 additions & 1 deletion
@@ -300,7 +300,7 @@ bool is_open() const;
 
 ### Return Value
 
-**true** if the file pointer isn't a null pointer.
+**true** if the file pointer is not null.
 
 ### Example
 
@@ -371,6 +371,8 @@ The default file opening protection, equivalent to the *shflag* parameter in [_f
 
 ### Return Value
 
+If the buffer is already open, the function returns a null pointer.
+
 If the file pointer is a null pointer, the function returns a null pointer. Otherwise, it returns **this**.
 
 ### Remarks