Predicate, an abstract base class for operators that return Bool

libwccl/ops/predicate.cpp

+#include <libwccl/ops/predicate.h>
+
+namespace Wccl {
+
+const boost::scoped_ptr< Constant<Bool> > Predicate::True(new Constant<Bool>(Bool(true)));
+
+const boost::scoped_ptr< Constant<Bool> > Predicate::False(new Constant<Bool>(Bool(false)));
+
+} /* end ns Wccl */

libwccl/ops/predicate.h

+#ifndef PREDICATE_H
+#define PREDICATE_H
+
+#include <boost/shared_ptr.hpp>
+#include <boost/scoped_ptr.hpp>
+
+#include <libwccl/values/bool.h>
+#include <libwccl/ops/functions.h>
+#include <libwccl/ops/constant.h>
+
+namespace Wccl {
+
+/**
+ * Abstract base class for Predicates (operators returning Bool)
+ */
+class Predicate : public Function<Bool> {
+public:
+	/**
+	 * Constant<Bool> holding true value, to use by predicates when returning value
+	 */
+	static const boost::scoped_ptr< Constant<Bool> > True;
+	/**
+	 * Constant<Bool> holding false value, to use by predicates when returning value
+	 */
+	static const boost::scoped_ptr< Constant<Bool> > False;
+};
+
+} /* end ns Wccl */
+
+#endif // PREDICATE_H