ClickHouse/base/poco/Foundation/include/Poco/Hash.h

//
// Hash.h
//
// Library: Foundation
// Package: Hashing
// Module:  Hash
//
// Definition of the Hash class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Foundation_Hash_INCLUDED
#define Foundation_Hash_INCLUDED


#include <cstddef>
#include "Poco/Foundation.h"


namespace Poco
{


std::size_t Foundation_API hash(Int8 n);
std::size_t Foundation_API hash(UInt8 n);
std::size_t Foundation_API hash(Int16 n);
std::size_t Foundation_API hash(UInt16 n);
std::size_t Foundation_API hash(Int32 n);
std::size_t Foundation_API hash(UInt32 n);
std::size_t Foundation_API hash(Int64 n);
std::size_t Foundation_API hash(UInt64 n);
std::size_t Foundation_API hash(const std::string & str);


template <class T>
struct Hash
/// A generic hash function.
{
    std::size_t operator()(T value) const
    /// Returns the hash for the given value.
    {
        return Poco::hash(value);
    }
};


//
// inlines
//
inline std::size_t hash(Int8 n)
{
    return static_cast<std::size_t>(n) * 2654435761U;
}


inline std::size_t hash(UInt8 n)
{
    return static_cast<std::size_t>(n) * 2654435761U;
}


inline std::size_t hash(Int16 n)
{
    return static_cast<std::size_t>(n) * 2654435761U;
}


inline std::size_t hash(UInt16 n)
{
    return static_cast<std::size_t>(n) * 2654435761U;
}


inline std::size_t hash(Int32 n)
{
    return static_cast<std::size_t>(n) * 2654435761U;
}


inline std::size_t hash(UInt32 n)
{
    return static_cast<std::size_t>(n) * 2654435761U;
}


inline std::size_t hash(Int64 n)
{
    return static_cast<std::size_t>(n) * 2654435761U;
}


inline std::size_t hash(UInt64 n)
{
    return static_cast<std::size_t>(n) * 2654435761U;
}


} // namespace Poco


#endif // Foundation_Hash_INCLUDED