/*

  This file is part of solidity.

  solidity is free software: you can redistribute it and/or modify

  it under the terms of the GNU General Public License as published by

  the Free Software Foundation, either version 3 of the License, or

  (at your option) any later version.

  solidity is distributed in the hope that it will be useful,

  but WITHOUT ANY WARRANTY; without even the implied warranty of

  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License

  along with solidity.  If not, see <http://www.gnu.org/licenses/>.

*/

// SPDX-License-Identifier: GPL-3.0

#pragma once

#include <libsolutil/Numeric.h>

#include <liblangutil/Exceptions.h>

#include <compare>

#include <cstddef>

#include <cstdint>

#include <limits>

namespace solidity::evmasm

{

/// Sub assembly ID representing class. Based on fixed-size 64-bit unsigned int.

/// An empty / root state is reflected by a value that is set to max and can be queried via the `empty()` member

/// function.

struct SubAssemblyID

{

  using ValueType = uint64_t;

  SubAssemblyID() = default;

  SubAssemblyID(ValueType const _value): value(_value) {}

  explicit SubAssemblyID(u256 const& _data)

  {

    solAssert(_data <= std::numeric_limits<ValueType>::max());

    value = static_cast<ValueType>(_data);

  }

  size_t asIndex() const

  {

    if constexpr(sizeof(ValueType) > sizeof(size_t))

    {

      solAssert(value < std::numeric_limits<size_t>::max());

      return static_cast<size_t>(value);

    }

    return value;

  }

  bool empty() const { return value == std::numeric_limits<ValueType>::max(); }

  auto operator<=>(SubAssemblyID const&) const = default;

  ValueType value = std::numeric_limits<ValueType>::max();

};

}