1 files changed, 75 insertions, 0 deletions
diff --git a/xpcom/base/nsAlgorithm.h b/xpcom/base/nsAlgorithm.h
new file mode 100644
index 0000000000..ceaa3ace33
--- /dev/null
+++ b/xpcom/base/nsAlgorithm.h
@@ -0,0 +1,75 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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& aA, const T& aB)
+{
+  return ((aA + (aB - 1)) / aB) * aB;
+}
+
+// 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& aA, const T& aB)
+{
+  return aB < aA ? aB : aA;
+}
+
+// Must return b when a == b in case a is -0
+template <class T>
+inline const T&
+XPCOM_MAX(const T& aA, const T& aB)
+{
+  return aA > aB ? aA : aB;
+}
+
+namespace mozilla {
+
+template <class T>
+inline const T&
+clamped(const T& aA, const T& aMin, const T& aMax)
+{
+  MOZ_ASSERT(aMax >= aMin,
+             "clamped(): aMax must be greater than or equal to aMin");
+  return XPCOM_MIN(XPCOM_MAX(aA, aMin), aMax);
+}
+
+} // namespace mozilla
+
+template <class InputIterator, class T>
+inline uint32_t
+NS_COUNT(InputIterator& aFirst, const InputIterator& aLast, const T& aValue)
+{
+  uint32_t result = 0;
+  for (; aFirst != aLast; ++aFirst)
+    if (*aFirst == aValue) {
+      ++result;
+    }
+  return result;
+}
+
+template <class InputIterator, class OutputIterator>
+inline OutputIterator&
+copy_string(const InputIterator& aFirst, const InputIterator& aLast,
+            OutputIterator& aResult)
+{
+  typedef nsCharSourceTraits<InputIterator> source_traits;
+  typedef nsCharSinkTraits<OutputIterator>  sink_traits;
+
+  sink_traits::write(aResult, source_traits::read(aFirst),
+                     source_traits::readable_distance(aFirst, aLast));
+  return aResult;
+}
+
+#endif // !defined(nsAlgorithm_h___)