mirror of https://github.com/facebook/rocksdb.git
57 lines
2.1 KiB
C++
57 lines
2.1 KiB
C++
// 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 <memory>
|
|
#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;
|
|
}
|
|
|
|
template <class DestClass, class SrcClass>
|
|
inline std::shared_ptr<DestClass> static_cast_with_check(
|
|
std::shared_ptr<SrcClass>&& x) {
|
|
#if defined(ROCKSDB_USE_RTTI) && !defined(NDEBUG)
|
|
auto orig_raw = x.get();
|
|
#endif
|
|
auto ret = std::static_pointer_cast<DestClass>(std::move(x));
|
|
#if defined(ROCKSDB_USE_RTTI) && !defined(NDEBUG)
|
|
assert(ret.get() == dynamic_cast<DestClass*>(orig_raw));
|
|
#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
|