75 lines
2.0 KiB
C++
75 lines
2.0 KiB
C++
/*
|
|
* Copyright (c) Facebook, Inc. and its affiliates.
|
|
*
|
|
* Licensed 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
|
|
*
|
|
* Unless required by applicable law or agreed to in writing, software
|
|
* distributed under the License is distributed on an "AS IS" BASIS,
|
|
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
* See the License for the specific language governing permissions and
|
|
* limitations under the License.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <cstdint>
|
|
#include <typeinfo>
|
|
|
|
#include <folly/CppAttributes.h>
|
|
#include <folly/detail/StaticSingletonManager.h>
|
|
|
|
namespace folly {
|
|
namespace detail {
|
|
|
|
class UniqueInstance {
|
|
public:
|
|
#if __GNUC__ && __GNUC__ < 7 && !__clang__
|
|
explicit UniqueInstance(...) noexcept {}
|
|
#else
|
|
template <template <typename...> class Z, typename... Key, typename... Mapped>
|
|
FOLLY_EXPORT FOLLY_ALWAYS_INLINE explicit UniqueInstance(
|
|
tag_t<Z<Key..., Mapped...>>, tag_t<Key...>, tag_t<Mapped...>) noexcept {
|
|
static Ptr const tmpl = &typeid(key_t<Z>);
|
|
static Ptr const ptrs[] = {&typeid(Key)..., &typeid(Mapped)...};
|
|
static Arg arg{
|
|
{tmpl, ptrs, sizeof...(Key), sizeof...(Mapped)},
|
|
{tag<Value, key_t<Z, Key...>>}};
|
|
enforce(arg);
|
|
}
|
|
#endif
|
|
|
|
UniqueInstance(UniqueInstance const&) = delete;
|
|
UniqueInstance(UniqueInstance&&) = delete;
|
|
UniqueInstance& operator=(UniqueInstance const&) = delete;
|
|
UniqueInstance& operator=(UniqueInstance&&) = delete;
|
|
|
|
private:
|
|
template <template <typename...> class Z, typename... Key>
|
|
struct key_t {};
|
|
|
|
using Ptr = std::type_info const*;
|
|
struct PtrRange {
|
|
Ptr const* b;
|
|
Ptr const* e;
|
|
};
|
|
struct Value {
|
|
Ptr tmpl;
|
|
Ptr const* ptrs;
|
|
std::uint32_t key_size;
|
|
std::uint32_t mapped_size;
|
|
};
|
|
struct Arg {
|
|
Value local;
|
|
StaticSingletonManager::ArgCreate<true> global;
|
|
};
|
|
|
|
static void enforce(Arg& arg) noexcept;
|
|
};
|
|
|
|
} // namespace detail
|
|
} // namespace folly
|