Mercurial > octave
view liboctave/util/action-container.h @ 31635:7d3467f8d713 stable
Backed out changeset d9970470108a
author | John W. Eaton <jwe@octave.org> |
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date | Sat, 03 Dec 2022 14:43:33 -0500 |
parents | d9970470108a |
children | 597f3ee61a48 |
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//////////////////////////////////////////////////////////////////////// // // Copyright (C) 1993-2022 The Octave Project Developers // // See the file COPYRIGHT.md in the top-level directory of this // distribution or <https://octave.org/copyright/>. // // This file is part of Octave. // // Octave is free software: you can redistribute it and/or modify it // under the terms of the GNU General Public License as published by // the Free Software Foundation, either version 3 of the License, or // (at your option) any later version. // // Octave is distributed in the hope that it will be useful, but // WITHOUT ANY WARRANTY; without even the implied warranty of // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the // GNU General Public License for more details. // // You should have received a copy of the GNU General Public License // along with Octave; see the file COPYING. If not, see // <https://www.gnu.org/licenses/>. // //////////////////////////////////////////////////////////////////////// #if ! defined (octave_action_container_h) #define octave_action_container_h 1 #include "octave-config.h" #include <cstddef> #include <functional> // This class allows registering actions in a list for later // execution, either explicitly or when the container goes out of // scope. // FIXME: is there a better name for this class? OCTAVE_BEGIN_NAMESPACE(octave) class action_container { public: // A generic unwind_protect element. Knows how to run itself and // discard itself. Also, contains a pointer to the next element. class elem { public: friend class action_container; elem (void) { } // No copying! elem (const elem&) = delete; elem& operator = (const elem&) = delete; virtual ~elem (void) = default; virtual void run (void) { } }; // An element that merely runs a void (*)(void) function. class fcn_elem : public elem { public: // FIXME: Do we need to apply std::forward to the arguments to // std::bind here? template <typename F, typename... Args> fcn_elem (F&& fcn, Args&& ... args) : m_fcn (std::bind (fcn, args...)) { } void run (void) { m_fcn (); } private: std::function<void (void)> m_fcn; }; // An element that stores arbitrary variable, and restores it. template <typename T> class restore_var_elem : public elem { public: restore_var_elem (T& ref, const T& val) : m_ptr (&ref), m_val (val) { } // No copying! restore_var_elem (const restore_var_elem&) = delete; restore_var_elem& operator = (const restore_var_elem&) = delete; void run (void) { *m_ptr = m_val; } private: T *m_ptr, m_val; }; // Deletes a class allocated using new. template <typename T> class delete_ptr_elem : public elem { public: delete_ptr_elem (T *ptr) : m_ptr (ptr) { } // No copying! delete_ptr_elem (const delete_ptr_elem&) = delete; delete_ptr_elem operator = (const delete_ptr_elem&) = delete; void run (void) { delete m_ptr; } private: T *m_ptr; }; action_container (void) { } // No copying! action_container (const action_container&) = delete; action_container& operator = (const action_container&) = delete; virtual ~action_container (void) = default; template <typename F, typename... Args> void add (F&& fcn, Args&& ... args) { add_action (new fcn_elem (std::forward<F> (fcn), std::forward<Args> (args)...)); } // Use separate template types for function pointer parameter // declarations and captured arguments so that differences in // const are handled properly. template <typename... Params, typename... Args> void add_fcn (void (*fcn) (Params...), Args&& ... args) { add_action (new fcn_elem (fcn, std::forward<Args> (args)...)); } template <typename T, typename... Params, typename... Args> void add_method (T *obj, void (T::*method) (Params...), Args&& ... args) { add_action (new fcn_elem (method, obj, std::forward<Args> (args)...)); } template <typename T, typename... Params, typename... Args> void add_method (T& obj, void (T::*method) (Params...), Args&& ... args) { add_action (new fcn_elem (method, &obj, std::forward<Args> (args)...)); } // Call to delete (T*). template <typename T> void add_delete (T *obj) { add_action (new delete_ptr_elem<T> (obj)); } // Protect any variable. template <typename T> void protect_var (T& var) { add_action (new restore_var_elem<T> (var, var)); } // Protect any variable, value given. template <typename T> void protect_var (T& var, const T& val) { add_action (new restore_var_elem<T> (var, val)); } operator bool (void) const { return ! empty (); } virtual void run_first (void) = 0; OCTAVE_API void run (std::size_t num); void run (void) { run (size ()); } virtual void discard_first (void) = 0; void discard (std::size_t num) { if (num > size ()) num = size (); for (std::size_t i = 0; i < num; i++) discard_first (); } void discard (void) { discard (size ()); } virtual std::size_t size (void) const = 0; bool empty (void) const { return size () == 0; } protected: virtual void add_action (elem *new_elem) = 0; }; OCTAVE_END_NAMESPACE(octave) #endif