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// Copyright 2019 The SwiftShader Authors. All Rights Reserved.
//
// 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.
#ifndef sw_ID_hpp
#define sw_ID_hpp
#include "System/Debug.hpp"
#include <cstdint>
#include <unordered_map>
namespace sw {
// SpirvID is a strongly-typed identifier backed by a uint32_t.
// The template parameter T is not actually used by the implementation of
// ID; instead it is used to prevent implicit casts between identifiers of
// different T types.
// IDs are typically used as a map key to value of type T.
template<typename T>
class SpirvID
{
public:
SpirvID() = default;
inline SpirvID(uint32_t id);
inline bool operator==(const SpirvID<T> &rhs) const;
inline bool operator!=(const SpirvID<T> &rhs) const;
inline bool operator<(const SpirvID<T> &rhs) const;
// Returns the numerical value of the identifier.
inline uint32_t value() const;
private:
uint32_t id = 0; // Valid ids are in the range "0 < id < Bound".
};
template<typename T>
SpirvID<T>::SpirvID(uint32_t id)
: id(id)
{}
template<typename T>
bool SpirvID<T>::operator==(const SpirvID<T> &rhs) const
{
return id == rhs.id;
}
template<typename T>
bool SpirvID<T>::operator!=(const SpirvID<T> &rhs) const
{
return id != rhs.id;
}
template<typename T>
bool SpirvID<T>::operator<(const SpirvID<T> &rhs) const
{
return id < rhs.id;
}
template<typename T>
uint32_t SpirvID<T>::value() const
{
// Assert that we don't attempt to use unassigned IDs.
// Use if(id != 0) { ... } to avoid invalid code paths.
ASSERT(id != 0);
return id;
}
// HandleMap<T> is an unordered map of SpirvID<T> to T.
template<typename T>
using HandleMap = std::unordered_map<SpirvID<T>, T>;
} // namespace sw
namespace std {
// std::hash implementation for sw::SpirvID<T>
template<typename T>
struct hash<sw::SpirvID<T> >
{
std::size_t operator()(const sw::SpirvID<T> &id) const noexcept
{
return std::hash<uint32_t>()(id.value());
}
};
} // namespace std
#endif // sw_ID_hpp