Flags.hpp

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#ifndef _FLAGS_HPP
#define _FLAGS_HPP

/// \file Flags.hpp
///
/// \brief Defines collectable flags
///
/// A flag is an integral value specifying the number of bits

#include <ints/IntSeq.hpp>

namespace SUNphi
{
  /// Create a mask for a given flag
  ///
  /// Shift right by the amount of bits
  template <auto Flag>
  [[ maybe_unused ]]
  constexpr int flagMask=
    1<<static_cast<int>(Flag);

  /// Combine flags to form a mask at compile time
  ///
  /// Internal implementation to catch error
  template <auto...Flags>   // Flags to be combined
  [[ maybe_unused ]]
  constexpr int _combineFlags()
  {
    STATIC_ASSERT_ARE_SAME(decltype(Flags)...);

    return (flagMask<Flags>|...);
  }

  /// Combine flags to form a mask at compile time
  ///
  /// Gives visibility to internal implementation
  template <auto...Flags>   // Flags to be combined
  [[ maybe_unused ]]
  constexpr int combineFlags=
       _combineFlags<Flags...>();

  /// Add flags to a mask at compile time
  template <int InMask,     // Incoming mask
        auto...Flags>   // Flags to be added
  [[ maybe_unused ]]
  constexpr int addFlags=
       InMask | combineFlags<Flags...>;

  /// Remove flags to a mask at compile time
  template <int InMask,     // Incoming mask
        auto...Flags>   // Flags to be removed
  [[ maybe_unused ]]
  constexpr int remFlags=
       InMask & ~combineFlags<Flags...>;

  /// Get a given flag from a mask
  template <int Mask,
        auto Flag>
  [[ maybe_unused ]]
  constexpr bool getFlag=
       Mask & flagMask<Flag>;
}

#endif