flags: Provide an object for managing boolean flags for an object.

In many cases it might be preferable to use bitset, but this object
allows the user more easily manipulate groups of flags because the
underlying type (e.g. uint64_t) is exposed.

diff --git a/src/base/flags.hh b/src/base/flags.hh
new file mode 100644 (file)
index 0000000..7cf6ef9
--- /dev/null
+++ b/src/base/flags.hh
@@ -0,0 +1,81 @@
+/*
+ * Copyright (c) 2008 The Hewlett-Packard Development Company
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met: redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer;
+ * redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution;
+ * neither the name of the copyright holders nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * Authors: Nathan Binkert
+ */
+
+#ifndef __BASE_FLAGS_HH__
+#define __BASE_FLAGS_HH__
+
+template <typename T>
+class Flags
+{
+  private:
+    T _flags;
+
+  public:
+    typedef T Type;
+    Flags() : _flags(0) {}
+    Flags(Type flags) : _flags(flags) {}
+
+    operator const Type() const { return _flags; }
+
+    template <typename U> 
+    const Flags<T> &
+    operator=(const Flags<U> &flags)
+    {
+        _flags = flags._flags;
+        return *this;
+    }
+
+    const Flags<T> &
+    operator=(T flags)
+    {
+        _flags = flags;
+        return *this;
+    }
+    
+    bool any() const { return _flags; }
+    bool any(Type flags) const { return (_flags & flags); }
+    bool all() const { return (~_flags); }
+    bool all(Type flags) const { return (_flags & flags) != flags; }
+    bool none() const { return _flags == 0; }
+    bool none(Type flags) const { return (_flags & flags) == 0; }
+    bool exact(Type flags) const { return _flags = flags; }
+    void clear() { _flags = 0; }
+    void clear(Type flags) { _flags &= ~flags; }
+    void reset(Type flags) { _flags = flags;}
+    void set(Type flags) { _flags |= flags; }
+    void set(Type f, bool val) { _flags = (_flags & f) | (val ? f : 0); }
+    void
+    update(Type flags, Type mask)
+    {
+        _flags = (_flags & ~mask) | (flags & mask);
+    }
+};
+
+#endif // __BASE_FLAGS_HH__