ATOOLS/YAML/setting.h

0001 #ifndef SETTING_H_62B23520_7C8E_11DE_8A39_0800200C9A66
0002 #define SETTING_H_62B23520_7C8E_11DE_8A39_0800200C9A66
0003
0004 #if defined(_MSC_VER) ||                                            \
0005     (defined(__GNUC__) && (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || \
0006      (__GNUC__ >= 4))  // GCC supports "pragma once" correctly since 3.4
0007 #pragma once
0008 #endif
0009
0010 #include "ATOOLS/YAML/yaml-cpp/noexcept.h"
0011 #include <memory>
0012 #include <utility>
0013 #include <vector>
0014
0015 namespace SHERPA_YAML {
0016
0017 class SettingChangeBase {
0018  public:
0019   virtual ~SettingChangeBase() = default;
0020   virtual void pop() = 0;
0021 };
0022
0023 template <typename T>
0024 class Setting {
0025  public:
0026   Setting() : m_value() {}
0027   Setting(const T& value) : m_value() { set(value); }
0028
0029   const T get() const { return m_value; }
0030   std::unique_ptr<SettingChangeBase> set(const T& value);
0031   void restore(const Setting<T>& oldSetting) { m_value = oldSetting.get(); }
0032
0033  private:
0034   T m_value;
0035 };
0036
0037 template <typename T>
0038 class SettingChange : public SettingChangeBase {
0039  public:
0040   SettingChange(Setting<T>* pSetting)
0041       : m_pCurSetting(pSetting),
0042         m_oldSetting(*pSetting)  // copy old setting to save its state
0043   {}
0044   SettingChange(const SettingChange&) = delete;
0045   SettingChange(SettingChange&&) = delete;
0046   SettingChange& operator=(const SettingChange&) = delete;
0047   SettingChange& operator=(SettingChange&&) = delete;
0048
0049   void pop() override { m_pCurSetting->restore(m_oldSetting); }
0050
0051  private:
0052   Setting<T>* m_pCurSetting;
0053   Setting<T> m_oldSetting;
0054 };
0055
0056 template <typename T>
0057 inline std::unique_ptr<SettingChangeBase> Setting<T>::set(const T& value) {
0058   std::unique_ptr<SettingChangeBase> pChange(new SettingChange<T>(this));
0059   m_value = value;
0060   return pChange;
0061 }
0062
0063 class SettingChanges {
0064  public:
0065   SettingChanges() : m_settingChanges{} {}
0066   SettingChanges(const SettingChanges&) = delete;
0067   SettingChanges(SettingChanges&&) YAML_CPP_NOEXCEPT = default;
0068   SettingChanges& operator=(const SettingChanges&) = delete;
0069   SettingChanges& operator=(SettingChanges&& rhs) YAML_CPP_NOEXCEPT {
0070     if (this == &rhs)
0071       return *this;
0072
0073     clear();
0074     std::swap(m_settingChanges, rhs.m_settingChanges);
0075
0076     return *this;
0077   }
0078   ~SettingChanges() { clear(); }
0079
0080   void clear() YAML_CPP_NOEXCEPT {
0081     restore();
0082     m_settingChanges.clear();
0083   }
0084
0085   void restore() YAML_CPP_NOEXCEPT {
0086     for (const auto& setting : m_settingChanges)
0087       setting->pop();
0088   }
0089
0090   void push(std::unique_ptr<SettingChangeBase> pSettingChange) {
0091     m_settingChanges.push_back(std::move(pSettingChange));
0092   }
0093
0094  private:
0095   using setting_changes = std::vector<std::unique_ptr<SettingChangeBase>>;
0096   setting_changes m_settingChanges;
0097 };
0098 }  // namespace SHERPA_YAML
0099
0100 #endif  // SETTING_H_62B23520_7C8E_11DE_8A39_0800200C9A66