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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-21 11:54:28 +0000 |
commit | e6918187568dbd01842d8d1d2c808ce16a894239 (patch) | |
tree | 64f88b554b444a49f656b6c656111a145cbbaa28 /src/rocksdb/util/cast_util.h | |
parent | Initial commit. (diff) | |
download | ceph-upstream/18.2.2.tar.xz ceph-upstream/18.2.2.zip |
Adding upstream version 18.2.2.upstream/18.2.2
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | src/rocksdb/util/cast_util.h | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/src/rocksdb/util/cast_util.h b/src/rocksdb/util/cast_util.h new file mode 100644 index 000000000..c91b6ff1e --- /dev/null +++ b/src/rocksdb/util/cast_util.h @@ -0,0 +1,42 @@ +// Copyright (c) 2011-present, Facebook, Inc. All rights reserved. +// This source code is licensed under both the GPLv2 (found in the +// COPYING file in the root directory) and Apache 2.0 License +// (found in the LICENSE.Apache file in the root directory). + +#pragma once + +#include <type_traits> + +#include "rocksdb/rocksdb_namespace.h" + +namespace ROCKSDB_NAMESPACE { +// The helper function to assert the move from dynamic_cast<> to +// static_cast<> is correct. This function is to deal with legacy code. +// It is not recommended to add new code to issue class casting. The preferred +// solution is to implement the functionality without a need of casting. +template <class DestClass, class SrcClass> +inline DestClass* static_cast_with_check(SrcClass* x) { + DestClass* ret = static_cast<DestClass*>(x); +#ifdef ROCKSDB_USE_RTTI + assert(ret == dynamic_cast<DestClass*>(x)); +#endif + return ret; +} + +// A wrapper around static_cast for lossless conversion between integral +// types, including enum types. For example, this can be used for converting +// between signed/unsigned or enum type and underlying type without fear of +// stripping away data, now or in the future. +template <typename To, typename From> +inline To lossless_cast(From x) { + using FromValue = typename std::remove_reference<From>::type; + static_assert( + std::is_integral<FromValue>::value || std::is_enum<FromValue>::value, + "Only works on integral types"); + static_assert(std::is_integral<To>::value || std::is_enum<To>::value, + "Only works on integral types"); + static_assert(sizeof(To) >= sizeof(FromValue), "Must be lossless"); + return static_cast<To>(x); +} + +} // namespace ROCKSDB_NAMESPACE |