include/Geant4/G4Filesystem.hh

0001 //
0002 // ********************************************************************
0003 // * License and Disclaimer                                           *
0004 // *                                                                  *
0005 // * The  Geant4 software  is  copyright of the Copyright Holders  of *
0006 // * the Geant4 Collaboration.  It is provided  under  the terms  and *
0007 // * conditions of the Geant4 Software License,  included in the file *
0008 // * LICENSE and available at  http://cern.ch/geant4/license .  These *
0009 // * include a list of copyright holders.                             *
0010 // *                                                                  *
0011 // * Neither the authors of this software system, nor their employing *
0012 // * institutes,nor the agencies providing financial support for this *
0013 // * work  make  any representation or  warranty, express or implied, *
0014 // * regarding  this  software system or assume any liability for its *
0015 // * use.  Please see the license in the file  LICENSE  and URL above *
0016 // * for the full disclaimer and the limitation of liability.         *
0017 // *                                                                  *
0018 // * This  code  implementation is the result of  the  scientific and *
0019 // * technical work of the GEANT4 collaboration.                      *
0020 // * By using,  copying,  modifying or  distributing the software (or *
0021 // * any work based  on the software)  you  agree  to acknowledge its *
0022 // * use  in  resulting  scientific  publications,  and indicate your *
0023 // * acceptance of all terms of the Geant4 Software license.          *
0024 // ********************************************************************
0025 #ifndef G4FILESYSTEM_HH
0026 #define G4FILESYSTEM_HH
0027 /**
0028  * @namespace G4fs
0029  * Namespace adapter for `filesystem` in `std::` or `std::experimental::`
0030  *
0031  * Developers should use this namespace to scope into the C++ filesystem
0032  * library, e.g.
0033  *
0034  * ```cpp
0035  * // Don't use std:: directly...
0036  * auto p = std::filesystem::path{ argv[0] };
0037  *
0038  * // ... use the alias
0039  * auto p = G4fs::path{ argv[0] };
0040  * ```
0041  *
0042  * This allows compatibility with C++ standard libraries that only provide
0043  * `filesystem` in the `std::experimental` namespace
0044  *
0045  */
0046 #if __has_include(<filesystem>)
0047 #  include <filesystem>
0048 namespace G4fs = std::filesystem;
0049 #elif __has_include(<experimental/filesystem>)
0050 #  include <experimental/filesystem>
0051 namespace G4fs = std::experimental::filesystem;
0052 #endif
0053
0054 #endif /* G4FILESYSTEM_HH */