flags.h

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/*
 * Copyright (c) 2003-2023, John Wiegley.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 *
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 *
 * - Neither the name of New Artisans LLC nor the names of its
 *   contributors may be used to endorse or promote products derived from
 *   this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
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 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
#pragma once
 
namespace ledger { namespace flags {
 
template <typename T = boost::uint_least8_t, typename U = T>
class supports_flags
{
public:
  typedef T flags_t;
 
protected:
  flags_t _flags;
 
public:
  supports_flags() : _flags(static_cast<T>(0)) {
    TRACE_CTOR(supports_flags, "");
  }
  supports_flags(const supports_flags& arg) : _flags(arg._flags) {
    TRACE_CTOR(supports_flags, "copy");
  }
  supports_flags(const flags_t& arg) : _flags(arg) {
    TRACE_CTOR(supports_flags, "const flags_t&");
  }
  ~supports_flags() throw() {
    TRACE_DTOR(supports_flags);
  }
 
  supports_flags& operator=(const supports_flags& other) {
    _flags = other._flags;
    return *this;
  }
 
  flags_t flags() const {
    return _flags;
  }
  bool has_flags(const flags_t arg) const {
    return _flags & arg;
  }
 
  void set_flags(const flags_t arg) {
    _flags = arg;
  }
  void clear_flags() {
    _flags = static_cast<T>(0);
  }
  void add_flags(const flags_t arg) {
    _flags = static_cast<T>(static_cast<U>(_flags) | static_cast<U>(arg));
  }
  void drop_flags(const flags_t arg) {
    _flags = static_cast<T>(static_cast<U>(_flags) & static_cast<U>(~arg));
  }
};
 
template <typename T = boost::uint_least8_t, typename U = T>
class basic_t : public supports_flags<T, U>
{
public:
  basic_t() {
    TRACE_CTOR(basic_t, "");
  }
  basic_t(const T& bits) {
    TRACE_CTOR(basic_t, "const T&");
    supports_flags<T, U>::set_flags(bits);
  }
  basic_t(const U& bits) {
    TRACE_CTOR(basic_t, "const U&");
    supports_flags<T, U>::set_flags(static_cast<T>(bits));
  }
  ~basic_t() throw() {
    TRACE_DTOR(basic_t);
  }
 
  basic_t(const basic_t& other)
    : supports_flags<T, U>(other) {
    TRACE_CTOR(basic_t, "copy");
  }
  basic_t& operator=(const basic_t& other) {
    set_flags(other.flags());
    return *this;
  }
  basic_t& operator=(const T& bits) {
    set_flags(bits);
    return *this;
  }
 
  operator T() const {
    return supports_flags<T, U>::flags();
  }
  operator U() const {
    return supports_flags<T, U>::flags();
  }
 
  basic_t plus_flags(const T& arg) const {
    basic_t temp(*this);
    temp.add_flags(arg);
    return temp;
  }
  basic_t minus_flags(const T& arg) const {
    basic_t temp(*this);
    temp.drop_flags(arg);
    return temp;
  }
};
 
template <typename T = boost::uint_least8_t>
class delegates_flags : public boost::noncopyable
{
public:
  typedef T flags_t;
 
protected:
  supports_flags<T>& _flags;
 
public:
  delegates_flags() : _flags() {
    TRACE_CTOR(delegates_flags, "");
  }
  delegates_flags(supports_flags<T>& arg) : _flags(arg) {
    TRACE_CTOR(delegates_flags, "const supports_flags<T>&");
  }
  ~delegates_flags() throw() {
    TRACE_DTOR(delegates_flags);
  }
 
  flags_t flags() const {
    return _flags.flags();
  }
  bool has_flags(const flags_t arg) const {
    return _flags.has_flags(arg);
  }
 
  void set_flags(const flags_t arg) {
    _flags.set_flags(arg);
  }
  void clear_flags() {
    _flags.clear_flags();
  }
  void add_flags(const flags_t arg) {
    _flags.add_flags(arg);
  }
  void drop_flags(const flags_t arg) {
    _flags.drop_flags(arg);
  }
};
 
} } // namespace ledger::flags