import FIREFOX_52_6_0esr_RELEASE from mozilla-esr52 hg repo

intl/icu/source/i18n/sharedbreakiterator.h

@@ -0,0 +1,49 @@
+// Copyright (C) 2016 and later: Unicode, Inc. and others.
+// License & terms of use: http://www.unicode.org/copyright.html
+/*
+******************************************************************************
+* Copyright (C) 2014, International Business Machines
+* Corporation and others.  All Rights Reserved.
+******************************************************************************
+* sharedbreakiterator.h
+*/
+
+#ifndef __SHARED_BREAKITERATOR_H__
+#define __SHARED_BREAKITERATOR_H__
+
+#include "unicode/utypes.h"
+#include "sharedobject.h"
+
+#if !UCONFIG_NO_BREAK_ITERATION
+
+U_NAMESPACE_BEGIN
+
+class BreakIterator;
+
+// SharedBreakIterator encapsulates a shared BreakIterator. Because
+// BreakIterator has mutable semantics, clients must ensure that all uses
+// of a particular shared BreakIterator is protected by the same mutex
+// ensuring that only one thread at a time gets access to that shared
+// BreakIterator. Clients can accomplish this by creating a mutex for all
+// uses of break iterator within a particular class. Then objects of that
+// class may then freely share break iterators among themselves. However,
+// these shared break iterators must never be exposed outside of that class.
+class U_I18N_API SharedBreakIterator : public SharedObject {
+public:
+    SharedBreakIterator(BreakIterator *biToAdopt);
+    virtual ~SharedBreakIterator();
+
+    BreakIterator *get() const { return ptr; }
+    BreakIterator *operator->() const { return ptr; }
+    BreakIterator &operator*() const { return *ptr; }
+private:
+    BreakIterator *ptr;
+    SharedBreakIterator(const SharedBreakIterator &);
+    SharedBreakIterator &operator=(const SharedBreakIterator &);
+};
+
+U_NAMESPACE_END
+
+#endif
+
+#endif