diff -r 000000000000 -r 6474c204b198 xpcom/string/public/nsAlgorithm.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/string/public/nsAlgorithm.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,76 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef nsAlgorithm_h___
+#define nsAlgorithm_h___
+
+#include "nsCharTraits.h"  // for |nsCharSourceTraits|, |nsCharSinkTraits|
+
+template <class T>
+inline
+T
+NS_ROUNDUP( const T& a, const T& b )
+  {
+    return ((a + (b - 1)) / b) * b;
+  }
+
+// We use these instead of std::min/max because we can't include the algorithm
+// header in all of XPCOM because the stl wrappers will error out when included
+// in parts of XPCOM. These functions should never be used outside of XPCOM.
+template <class T>
+inline
+const T&
+XPCOM_MIN( const T& a, const T& b )
+  {
+    return b < a ? b : a;
+  }
+
+// Must return b when a == b in case a is -0
+template <class T>
+inline
+const T&
+XPCOM_MAX( const T& a, const T& b )
+  {
+    return a > b ? a : b;
+  }
+
+namespace mozilla {
+
+template <class T>
+inline
+const T&
+clamped( const T& a, const T& min, const T& max )
+  {
+    NS_ABORT_IF_FALSE(max >= min, "clamped(): max must be greater than or equal to min");
+    return XPCOM_MIN(XPCOM_MAX(a, min), max);
+  }
+
+}
+
+template <class InputIterator, class T>
+inline
+uint32_t
+NS_COUNT( InputIterator& first, const InputIterator& last, const T& value )
+  {
+    uint32_t result = 0;
+    for ( ; first != last; ++first )
+      if ( *first == value )
+        ++result;
+    return result;
+  }
+
+template <class InputIterator, class OutputIterator>
+inline
+OutputIterator&
+copy_string( const InputIterator& first, const InputIterator& last, OutputIterator& result )
+  {
+    typedef nsCharSourceTraits<InputIterator> source_traits;
+    typedef nsCharSinkTraits<OutputIterator>  sink_traits;
+
+    sink_traits::write(result, source_traits::read(first), source_traits::readable_distance(first, last));
+    return result;
+  }
+
+#endif // !defined(nsAlgorithm_h___)