details that symbolize_keys symbolizes keys as long as they respond to to_sym (so "all" may not be really all)

1 files changed, 4 insertions, 2 deletions

diff --git a/activesupport/lib/active_support/core_ext/hash/keys.rb b/activesupport/lib/active_support/core_ext/hash/keys.rb
index ffaa69570f..ecd63293b4 100644
--- a/activesupport/lib/active_support/core_ext/hash/keys.rb
+++ b/activesupport/lib/active_support/core_ext/hash/keys.rb
@@ -15,7 +15,8 @@ class Hash
     self
   end
 
-  # Return a new hash with all keys converted to symbols.
+  # Return a new hash with all keys converted to symbols, as long as
+  # they respond to +to_sym+.
   def symbolize_keys
     inject({}) do |options, (key, value)|
       options[(key.to_sym rescue key) || key] = value
@@ -23,7 +24,8 @@ class Hash
     end
   end
 
-  # Destructively convert all keys to symbols.
+  # Destructively convert all keys to symbols, as long as they respond
+  # to +to_sym+.
   def symbolize_keys!
     self.replace(self.symbolize_keys)
   end