#ifndef SETTING_H_62B23520_7C8E_11DE_8A39_0800200C9A66 #define SETTING_H_62B23520_7C8E_11DE_8A39_0800200C9A66 #if defined(_MSC_VER) || \ (defined(__GNUC__) && (__GNUC__ == 3 && __GNUC_MINOR__ >= 4) || \ (__GNUC__ >= 4)) // GCC supports "pragma once" correctly since 3.4 #pragma once #endif #include #include #include "yaml-cpp/noncopyable.h" namespace SHERPA_YAML { class SettingChangeBase; template class Setting { public: Setting() : m_value() {} const T get() const { return m_value; } std::unique_ptr set(const T& value); void restore(const Setting& oldSetting) { m_value = oldSetting.get(); } private: T m_value; }; class SettingChangeBase { public: virtual ~SettingChangeBase() {} virtual void pop() = 0; }; template class SettingChange : public SettingChangeBase { public: SettingChange(Setting* pSetting) : m_pCurSetting(pSetting) { // copy old setting to save its state m_oldSetting = *pSetting; } virtual void pop() { m_pCurSetting->restore(m_oldSetting); } private: Setting* m_pCurSetting; Setting m_oldSetting; }; template inline std::unique_ptr Setting::set(const T& value) { std::unique_ptr pChange(new SettingChange(this)); m_value = value; return pChange; } class SettingChanges : private noncopyable { public: SettingChanges() {} ~SettingChanges() { clear(); } void clear() { restore(); m_settingChanges.clear(); } void restore() { for (setting_changes::const_iterator it = m_settingChanges.begin(); it != m_settingChanges.end(); ++it) (*it)->pop(); } void push(std::unique_ptr pSettingChange) { m_settingChanges.push_back(std::move(pSettingChange)); } // like std::unique_ptr - assignment is transfer of ownership SettingChanges& operator=(SettingChanges&& rhs) { if (this == &rhs) return *this; clear(); std::swap(m_settingChanges, rhs.m_settingChanges); return *this; } private: typedef std::vector> setting_changes; setting_changes m_settingChanges; }; } #endif // SETTING_H_62B23520_7C8E_11DE_8A39_0800200C9A66