enum_flags_without_ostream.h

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//    Copyright 2022, farm-ng 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.
 
// FARM_ENUM is a fork of MY_ENUM.
//
// https://github.com/facebookincubator/MY_ENUM/
//
// Copyright (c) Facebook, Inc. and its affiliates.
//
// This source code is licensed under the MIT license found in the
// LICENSE file in the root directory of this source tree.
 
#pragma once
 
#include "farm_ng/core/enum/impl/enum_flag_details.h"
 
/* FARM_ENUMFLAGS_WITHOUT_OSTREAM_DEF(NAME, UINT_TYPE, ARGS)
 
  Enum flags type definition. Can be in global, and namespace scope only. See
  FARM_ENUMFLAGS_WITHOUT_OSTREAM below for details. */
#define FARM_ENUMFLAGS_WITHOUT_OSTREAM_DEF(NAME, UINT_TYPE, ...) \
  FARM_ENUMFLAGS_DEF_IMPL(NAME, UINT_TYPE, __VA_ARGS__)
 
/* FARM_ENUMFLAGS_ALIAS(NAME)
 
  Enum type alias. Can be in any scope. See FARM_ENUMFLAGS_WITHOUT_OSTREAM for
  details. */
#define FARM_ENUMFLAGS_ALIAS(NAME) using NAME = enum_wrapper_::NAME##Impl
 
/* FARM_ENUMFLAGS_WITHOUT_OSTREAM(NAME, UINT_TYPE, ARGS)
 
  Enum flag type. Can be in global, and namespace scope only.
 
      NAME:      Name of the enum flag class.
      UINT_TYPE: unsigned integral type.
      ARGS:      Tuple of enums, such as (foo, bar, da).
 
  For example ``FARM_ENUMFLAGS_WITHOUT_OSTREAM(MyFlags, uint32_t, (foo, bar,
  daz));`` defines an enum class
 
    enum class MyFlags : uint32_t {
      none = 0,
      foo = 1,
      bar = 2,
      daz = 4
    };
 
  with the following free functions:
 
    // Bitwise or
    MyFlags operator|(MyFlags left, MyFlags right);
 
    // Bitwise and
    MyFlags operator&(MyFlags left, MyFlags right);
 
    // Sets corresponding bit to 1, if string is single flag (i.e. "foo", "bar"
    // or "daz"). Returns false otherwise.
    bool trySetFlagFromString(MyFlags& value, const std::string& str);
 
    // Return true if ``value`` contains all flags in ``mask``.
    bool hasMask(MyFlags value, MyFlags mask);
 
    // Enables bits in mask.
    void setMask(MyFlags& value, MyFlags mask);
 
    // Clear bits in mask.
    void clearMask(MyFlags& value, MyFlags mask);
 
    // Toggle bits.
    void toggleMask(MyFlags& value, MyFlags mask);
 
    // Returns true if value is a single flag (i.e. Foo::foo, Foo::bar or
    // Foo::daz)
    bool isSingleFlag(MyFlags value);
 
    // Returns string representation of enabled flags
    // (e.g. {"foo", "bar"} for `MyFlags::foo | MyFlags::bar')
    std::vector<std::string> toStrings(MyFlags value);
 
    // Return pretty string representation
    // (e.g. "{bar (=2), daz (=4)}" for `MyFlags::bar | MyFlags::daz').
    std::string toPretty(MyFlags value);
 
    // Returns number of flags (i.e. 3).
    constexpr size_t getCount(MyFlags) {
      return 3u;
    }
 
    // Returns array of names:
    std::array<string_view, 3> getNames(MyFlags) {
      return {"foo", "bar", "daz"};
    }
 
    // Return string of names:
    constexpr string_view getStringOfNames(MyFlags) {
      return "{foo, bar, daz}";
    }
 
    // Returns array of values:
    constexpr std::array<uint32_t, 3u> getValues(MyFlags) {
      return {1, 2, 4};
    }
 
    string_view getTypeName(MyFlags) {
      return "MyFlags";
    }
 
   // Note: When adding new flags to an existing enum, we want to add such flag
   // at the end.
 
    FARM_ENUMFLAGS_WITHOUT_OSTREAM(MyFlags, uint32_t, (foo, bar));
 
      generates
 
    enum class MyFlags : uint32_t {
      none = 0,
      foo = 1,
      bar = 2
    };
 
 
    Now adding "daz" to the end, we get
 
 
    FARM_ENUMFLAGS_WITHOUT_OSTREAM(MyFlags, uint32_t, (foo, bar, daz));
 
      which generates
 
    enum class MyFlags : uint32_t {
      none = 0,
      foo = 1,
      bar = 2,
      daz = 4
    };
 
    And hence the order of exiting flags (foo, bar) is respected and their
    values do not change.
*/
#define FARM_ENUMFLAGS_WITHOUT_OSTREAM(NAME, UINT_TYPE, ...)       \
  FARM_ENUMFLAGS_WITHOUT_OSTREAM_DEF(NAME, UINT_TYPE, __VA_ARGS__) \
  FARM_ENUMFLAGS_ALIAS(NAME)