diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index aea11172db9..4c564e898bb 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,3 +1,8 @@
+2013-12-03  Tim Shen  <timshen91@gmail.com>
+
+	* regex_compiler.h: Add todo comment.
+	* regex_executor.tcc: Likewise.
+
 2013-11-29  Matthias Klose  <doko@ubuntu.com>
 
 	* testsuite/experimental/string_view/requirements/exception,
diff --git a/libstdc++-v3/include/bits/regex_compiler.h b/libstdc++-v3/include/bits/regex_compiler.h
index b9f81272bb9..5759d48c5e5 100644
--- a/libstdc++-v3/include/bits/regex_compiler.h
+++ b/libstdc++-v3/include/bits/regex_compiler.h
@@ -237,6 +237,10 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
     };
 
   /// Matches a character range (bracket expression)
+  // TODO: Convert used _M_flags fields to template parameters, including
+  // collate and icase. Avoid using std::set, could use flat_set
+  // (sorted vector and binary search) instead; use an fixed sized (256)
+  // vector<bool> for char specialization if necessary.
   template<typename _TraitsT>
     struct _BracketMatcher
     {
diff --git a/libstdc++-v3/include/bits/regex_executor.tcc b/libstdc++-v3/include/bits/regex_executor.tcc
index 22fd67cfa3b..150adb4f2df 100644
--- a/libstdc++-v3/include/bits/regex_executor.tcc
+++ b/libstdc++-v3/include/bits/regex_executor.tcc
@@ -162,6 +162,7 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
       return false;
     }
 
+  // TODO: Use a function vector to dispatch, instead of using switch-case.
   template<typename _BiIter, typename _Alloc, typename _TraitsT,
     bool __dfs_mode>
   template<bool __match_mode>