invalid_values.hpp

// This file is part of the ACTS project.
//
// Copyright (C) 2016 CERN for the benefit of the ACTS project
//
// This Source Code Form is subject to the terms of the Mozilla Public
// License, v. 2.0. If a copy of the MPL was not distributed with this
// file, You can obtain one at https://mozilla.org/MPL/2.0/.
 
#pragma once
 
// Project include(s).
#include "detray/definitions/detail/qualifiers.hpp"
 
// System include(s)
#include <limits>
#include <type_traits>
 
namespace detray::detail {

template <typename T>
  requires std::is_fundamental_v<T> || std::is_enum_v<T>
DETRAY_HOST_DEVICE constexpr T invalid_value() noexcept {
  return std::numeric_limits<T>::max();
}

template <typename T>
  requires(!std::is_fundamental_v<T>) && (!std::is_enum_v<T>) &&
          std::is_default_constructible_v<T>
DETRAY_HOST_DEVICE constexpr T invalid_value() noexcept {
  return T{};
}
 
template <typename T>
  requires std::is_fundamental_v<T>
DETRAY_HOST_DEVICE constexpr bool is_invalid_value(const T value) noexcept {
  if constexpr (std::is_signed_v<T>) {
    return (value == detail::invalid_value<T>() ||
            value == -detail::invalid_value<T>());
  } else {
    return (value == detail::invalid_value<T>());
  }
}
 
template <typename T>
  requires(!std::is_fundamental_v<T>)
DETRAY_HOST_DEVICE constexpr bool is_invalid_value(const T& value) noexcept {
  return (value == detail::invalid_value<T>());
}
 
}  // namespace detray::detail