text: // Copyright (c) 2018-present, Netifi Inc.
  //
  // 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.
  
  #pragma once
  
  #include <cstdint>
  #include <iosfwd>
  
  namespace proteus {
  
  enum class FrameFlags : uint16_t {
    EMPTY = 0x000,
    IGNORE = 0x200,
    METADATA = 0x100,
  
    // SETUP.
    RESUME_ENABLE = 0x80,
    LEASE = 0x40,
  
    // KEEPALIVE
    KEEPALIVE_RESPOND = 0x80,
  
    // REQUEST_RESPONSE, REQUEST_FNF, REQUEST_STREAM, REQUEST_CHANNEL, PAYLOAD.
    FOLLOWS = 0x80,
  
    // REQUEST_CHANNEL, PAYLOAD.
    COMPLETE = 0x40,
  
    // PAYLOAD.
    NEXT = 0x20,
  };
  
  constexpr uint16_t raw(FrameFlags flags) {
    return static_cast<uint16_t>(flags);
  }
  
  constexpr FrameFlags operator|(FrameFlags a, FrameFlags b) {
    return static_cast<FrameFlags>(raw(a) | raw(b));
  }
  
  constexpr FrameFlags operator&(FrameFlags a, FrameFlags b) {
    return static_cast<FrameFlags>(raw(a) & raw(b));
  }
  
  inline FrameFlags& operator|=(FrameFlags& a, FrameFlags b) {
    return a = (a | b);
  }
  
  inline FrameFlags& operator&=(FrameFlags& a, FrameFlags b) {
    return a = (a & b);
  }
  
  constexpr bool operator!(FrameFlags a) {
    return !raw(a);
  }
  
  constexpr FrameFlags operator~(FrameFlags a) {
    return static_cast<FrameFlags>(~raw(a));
  }
  
  std::ostream& operator<<(std::ostream& ostr, FrameFlags a);
  
  } // namespace proteus
  