diff --git a/Makefile.am b/Makefile.am
index 76226e1d..ab78f268 100644
--- a/Makefile.am
+++ b/Makefile.am
@@ -137,6 +137,8 @@ UTIL_FILES = \
stream.hpp \
string.cpp \
string.hpp \
+ stringid.cpp \
+ stringid.hpp \
time.cpp \
time.hpp \
types.hpp \
diff --git a/stringid.cpp b/stringid.cpp
new file mode 100644
index 00000000..25b12dbf
--- /dev/null
+++ b/stringid.cpp
@@ -0,0 +1,61 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libgim. If not, see .
+ *
+ * Copyright 2014 Danny Robson
+ */
+
+#include "stringid.hpp"
+
+#include "raii.hpp"
+
+#include
+#include
+
+using util::stringid;
+
+
+//-----------------------------------------------------------------------------
+stringid::id_t
+stringid::add (const std::string key) {
+ auto pos = m_map.find (key);
+ if (pos != m_map.end ())
+ throw std::invalid_argument ("duplicate stringid key");
+
+ static std::mutex s_lock;
+ std::lock_guard raii (s_lock);
+
+ id_t id = m_map.size ();
+ m_map[key] = id;
+ return id;
+}
+
+
+//-----------------------------------------------------------------------------
+stringid::id_t
+stringid::find (const std::string &key) const {
+ auto pos = m_map.find (key);
+ if (pos == m_map.end ())
+ throw std::out_of_range ("invalid stringid key");
+
+ return pos->second;
+}
+
+
+//-----------------------------------------------------------------------------
+void
+stringid::clear (void) {
+ m_map.clear ();
+}
diff --git a/stringid.hpp b/stringid.hpp
new file mode 100644
index 00000000..3601ce5b
--- /dev/null
+++ b/stringid.hpp
@@ -0,0 +1,41 @@
+/*
+ * This file is part of libgim.
+ *
+ * libgim is free software: you can redistribute it and/or modify it under the
+ * terms of the GNU General Public License as published by the Free Software
+ * Foundation, either version 3 of the License, or (at your option) any later
+ * version.
+ *
+ * libgim is distributed in the hope that it will be useful, but WITHOUT ANY
+ * WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
+ * FOR A PARTICULAR PURPOSE. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with libgim. If not, see .
+ *
+ * Copyright 2014 Danny Robson
+ */
+
+#ifndef __UTIL_STRINGID_HPP
+#define __UTIL_STRINGID_HPP
+
+#include