Documentation work

include/beast/http/fields.hpp

@@ -196,6 +196,16 @@ public:
         return list_.cend();
     }
 
+    /// Return `true` if the specified field exists.
+    bool
+    exists(field f) const
+    {
+        // VFALCO Should we throw here?
+        if(f == field::unknown)
+            return false;
+        return set_.find(to_string(f), less{}) != set_.end();
+    }
+
     /// Return `true` if the specified field exists.
     bool
     exists(string_view name) const