create a macro library for implementing bit-flags types

Signed-off-by: Stephan Bergmann <sbergman@redhat.com>,
changed from a macro- to a template-based solution.  (Unfortunately MSVC 2012
does not support explicit conversion operators.  Worked around that with
explicit #ifs rather than some HAVE_EXPLICIT_CONVERSION_OPERATORS and
SAL_EXPLICIT_CONVERSION_OPERATOR ainticipating we hopefully soon move to a
baseline that requires unconditional support for them.)

Change-Id: I4a89643b218d247e8e4a861faba458ec6dfe1396

1 files changed, 208 insertions, 0 deletions

diff --git a/include/o3tl/typed_flags_set.hxx b/include/o3tl/typed_flags_set.hxx
new file mode 100644
index 000000000000..baa679354de5
--- /dev/null
+++ b/include/o3tl/typed_flags_set.hxx
@@ -0,0 +1,208 @@
+/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
+/*
+ * This file is part of the LibreOffice project.
+ *
+ * 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/.
+ *
+ * This file incorporates work covered by the following license notice:
+ *
+ *   Licensed to the Apache Software Foundation (ASF) under one or more
+ *   contributor license agreements. See the NOTICE file distributed
+ *   with this work for additional information regarding copyright
+ *   ownership. The ASF licenses this file to you under the Apache
+ *   License, Version 2.0 (the "License"); you may not use this file
+ *   except in compliance with the License. You may obtain a copy of
+ *   the License at http://www.apache.org/licenses/LICENSE-2.0 .
+ */
+
+#ifndef INCLUDED_O3TL_TYPED_FLAGS_SET_HXX
+#define INCLUDED_O3TL_TYPED_FLAGS_SET_HXX
+
+#include <sal/config.h>
+
+#include <cassert>
+#include <type_traits>
+
+namespace o3tl {
+
+template<typename T> struct typed_flags {};
+
+/// Mark a (scoped) enumeration as a set of bit flags, with accompanying
+/// operations.
+///
+///   template<>
+///   struct o3tl::typed_flags<TheE>: o3tl::is_typed_flags<TheE, TheM> {};
+///
+/// All relevant values must be non-negative.  (Typically, the enumeration's
+/// underlying type will either be fixed and unsigned, or it will be unfixed---
+/// and can thus default to a signed type---and all enumerators will have non-
+/// negative values.)
+///
+/// \param E the enumeration type.
+/// \param M the all-bits-set value for the bit flags.
+template<typename E, typename std::underlying_type<E>::type M>
+struct is_typed_flags {
+    static_assert(
+        M >= 0, "is_typed_flags expects only non-negative bit values");
+
+    class Self {
+    public:
+        explicit Self(typename std::underlying_type<E>::type value):
+            value_(value)
+        { assert(value >= 0); }
+
+        operator E() { return static_cast<E>(value_); }
+
+#if !defined _MSC_VER || _MSC_VER > 1700
+        explicit
+#endif
+        operator typename std::underlying_type<E>::type() { return value_; }
+
+#if !defined _MSC_VER || _MSC_VER > 1700
+        explicit
+#endif
+        operator bool() { return value_ != 0; }
+
+    private:
+        typename std::underlying_type<E>::type value_;
+    };
+
+    static typename std::underlying_type<E>::type const mask = M;
+};
+
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator ~(E rhs) {
+    assert(static_cast<typename std::underlying_type<E>::type>(rhs) >= 0);
+    return static_cast<typename o3tl::typed_flags<E>::Self>(
+        o3tl::typed_flags<E>::mask
+        & ~static_cast<typename std::underlying_type<E>::type>(rhs));
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator ~(
+    typename o3tl::typed_flags<E>::Self rhs)
+{
+    return static_cast<typename o3tl::typed_flags<E>::Self>(
+        o3tl::typed_flags<E>::mask
+        & ~static_cast<typename std::underlying_type<E>::type>(rhs));
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator &(E lhs, E rhs) {
+    assert(static_cast<typename std::underlying_type<E>::type>(lhs) >= 0);
+    assert(static_cast<typename std::underlying_type<E>::type>(rhs) >= 0);
+    return static_cast<typename o3tl::typed_flags<E>::Self>(
+        static_cast<typename std::underlying_type<E>::type>(lhs)
+        & static_cast<typename std::underlying_type<E>::type>(rhs));
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator &(
+    E lhs, typename o3tl::typed_flags<E>::Self rhs)
+{
+    assert(static_cast<typename std::underlying_type<E>::type>(lhs) >= 0);
+    return static_cast<typename o3tl::typed_flags<E>::Self>(
+        static_cast<typename std::underlying_type<E>::type>(lhs)
+        & static_cast<typename std::underlying_type<E>::type>(rhs));
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator &(
+    typename o3tl::typed_flags<E>::Self lhs, E rhs)
+{
+    assert(static_cast<typename std::underlying_type<E>::type>(rhs) >= 0);
+    return static_cast<typename o3tl::typed_flags<E>::Self>(
+        static_cast<typename std::underlying_type<E>::type>(lhs)
+        & static_cast<typename std::underlying_type<E>::type>(rhs));
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator &(
+    typename o3tl::typed_flags<E>::Self lhs,
+    typename o3tl::typed_flags<E>::Self rhs)
+{
+    return static_cast<typename o3tl::typed_flags<E>::Self>(
+        static_cast<typename std::underlying_type<E>::type>(lhs)
+        & static_cast<typename std::underlying_type<E>::type>(rhs));
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator |(E lhs, E rhs) {
+    assert(static_cast<typename std::underlying_type<E>::type>(lhs) >= 0);
+    assert(static_cast<typename std::underlying_type<E>::type>(rhs) >= 0);
+    return static_cast<typename o3tl::typed_flags<E>::Self>(
+        static_cast<typename std::underlying_type<E>::type>(lhs)
+        | static_cast<typename std::underlying_type<E>::type>(rhs));
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator |(
+    E lhs, typename o3tl::typed_flags<E>::Self rhs)
+{
+    assert(static_cast<typename std::underlying_type<E>::type>(lhs) >= 0);
+    return static_cast<typename o3tl::typed_flags<E>::Self>(
+        static_cast<typename std::underlying_type<E>::type>(lhs)
+        | static_cast<typename std::underlying_type<E>::type>(rhs));
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator |(
+    typename o3tl::typed_flags<E>::Self lhs, E rhs)
+{
+    assert(static_cast<typename std::underlying_type<E>::type>(rhs) >= 0);
+    return static_cast<typename o3tl::typed_flags<E>::Self>(
+        static_cast<typename std::underlying_type<E>::type>(lhs)
+        | static_cast<typename std::underlying_type<E>::type>(rhs));
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator |(
+    typename o3tl::typed_flags<E>::Self lhs,
+    typename o3tl::typed_flags<E>::Self rhs)
+{
+    return static_cast<typename o3tl::typed_flags<E>::Self>(
+        static_cast<typename std::underlying_type<E>::type>(lhs)
+        | static_cast<typename std::underlying_type<E>::type>(rhs));
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator &=(E & lhs, E rhs) {
+    assert(static_cast<typename std::underlying_type<E>::type>(lhs) >= 0);
+    assert(static_cast<typename std::underlying_type<E>::type>(rhs) >= 0);
+    lhs = lhs & rhs;
+    return lhs;
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator &=(
+    E & lhs, typename o3tl::typed_flags<E>::Self rhs)
+{
+    assert(static_cast<typename std::underlying_type<E>::type>(lhs) >= 0);
+    lhs = lhs & rhs;
+    return lhs;
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator |=(E & lhs, E rhs) {
+    assert(static_cast<typename std::underlying_type<E>::type>(lhs) >= 0);
+    assert(static_cast<typename std::underlying_type<E>::type>(rhs) >= 0);
+    lhs = lhs | rhs;
+    return lhs;
+}
+
+template<typename E>
+inline typename o3tl::typed_flags<E>::Self operator |=(
+    E & lhs, typename o3tl::typed_flags<E>::Self rhs)
+{
+    assert(static_cast<typename std::underlying_type<E>::type>(lhs) >= 0);
+    lhs = lhs | rhs;
+    return lhs;
+}
+
+#endif /* INCLUDED_O3TL_TYPED_FLAGS_SET_HXX */
+
+/* vim:set shiftwidth=4 softtabstop=4 expandtab: */