cpp-common: rename `bt2_common` namespace -> `bt2c`

[babeltrace.git] / src / cpp-common / bt2c / safe-ops.hpp

diff --git a/src/cpp-common/bt2c/safe-ops.hpp b/src/cpp-common/bt2c/safe-ops.hpp
new file mode 100644 (file)
index 0000000..e1d6601
--- /dev/null
+++ b/src/cpp-common/bt2c/safe-ops.hpp
@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2022 Philippe Proulx <pproulx@efficios.com>
+ *
+ * SPDX-License-Identifier: MIT
+ */
+
+#ifndef BABELTRACE_CPP_COMMON_BT2C_SAFE_OPS_HPP
+#define BABELTRACE_CPP_COMMON_BT2C_SAFE_OPS_HPP
+
+#include <limits>
+#include <type_traits>
+
+#include "common/assert.h"
+
+namespace bt2c {
+
+template <typename T>
+constexpr bool safeToMul(const T a, const T b)
+{
+    static_assert(std::is_unsigned<T>::value, "`T` is an unsigned type.");
+
+    return a == 0 || b == 0 || a < std::numeric_limits<T>::max() / b;
+}
+
+template <typename T>
+T safeMul(const T a, const T b) noexcept
+{
+    static_assert(std::is_unsigned<T>::value, "`T` is an unsigned type.");
+
+    BT_ASSERT_DBG(safeToMul(a, b));
+    return a * b;
+}
+
+template <typename T>
+constexpr bool safeToAdd(const T a, const T b)
+{
+    static_assert(std::is_unsigned<T>::value, "`T` is an unsigned type.");
+
+    return a <= std::numeric_limits<T>::max() - b;
+}
+
+template <typename T>
+T safeAdd(const T a, const T b) noexcept
+{
+    static_assert(std::is_unsigned<T>::value, "`T` is an unsigned type.");
+
+    BT_ASSERT_DBG(safeToAdd(a, b));
+    return a + b;
+}
+
+template <typename T>
+constexpr bool safeToSub(const T a, const T b)
+{
+    static_assert(std::is_unsigned<T>::value, "`T` is an unsigned type.");
+
+    return a >= b;
+}
+
+template <typename T>
+T safeSub(const T a, const T b) noexcept
+{
+    static_assert(std::is_unsigned<T>::value, "`T` is an unsigned type.");
+
+    BT_ASSERT_DBG(safeToSub(a, b));
+    return a - b;
+}
+
+} /* namespace bt2c */
+
+#endif /* BABELTRACE_CPP_COMMON_BT2C_SAFE_OPS_HPP */