1 files changed, 29 insertions, 0 deletions
diff --git a/src/lib/util/doubles.h b/src/lib/util/doubles.h
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+++ b/src/lib/util/doubles.h
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+// Copyright (C) 2019 Internet Systems Consortium, Inc. ("ISC")
+//
+// 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 DOUBLES_H
+#define DOUBLES_H
+
+#include <complex>
+
+namespace isc {
+namespace util {
+
+/// @brief Tests two doubles for equivalence within a given tolerance.
+///
+/// @param a comparison operand one
+/// @param b comparison operand two
+/// @param tolerance the amount by which the two values may differ and
+/// still be considered "equal".
+/// @return True if the two values differ by less than the tolerance.
+inline bool areDoublesEquivalent(double a, double b, double tolerance=0.000001) {
+    return(std::abs(a - b) < tolerance);
+}
+
+} // namespace util
+} // namespace isc
+
+#endif // DOUBLES_H