Use experimental/ghc filesystem for meson builds

macos/Dependencies/dependencies.make

@@ -94,7 +94,7 @@ $(DOWNLOADS)/sigcxx/Makefile: $(DOWNLOADS)/sigcxx/autogen.sh
 	$(AUTOGEN) --enable-static=yes --enable-shared=no
 
 $(DOWNLOADS)/sigcxx/autogen.sh:
-	$(CLONE) $(GITLAB)/mkxp-z/libsigcplusplus $(DOWNLOADS)/sigcxx
+	$(CLONE) $(GITLAB)/mkxp-z/libsigcplusplus -b libsigc++-2-10 $(DOWNLOADS)/sigcxx
 
 # Pixman
 pixman: init_dirs libpng $(LIBDIR)/libpixman-1.a

macos/mkxp-z.xcodeproj/project.pbxproj

@@ -118,7 +118,6 @@
 		3B10EE092568E96A00372D13 /* binding-mri.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 3B10EDF02568E96A00372D13 /* binding-mri.cpp */; };
 		3B10EE0B2568E96A00372D13 /* module_rpg.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 3B10EDF32568E96A00372D13 /* module_rpg.cpp */; };
 		3B10EE0C2568E96A00372D13 /* viewport-binding.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 3B10EDF42568E96A00372D13 /* viewport-binding.cpp */; };
-		3B426F29256B6C75009EA00F /* libsigc-3.0.a in Frameworks */ = {isa = PBXBuildFile; fileRef = 3B426F28256B6C75009EA00F /* libsigc-3.0.a */; };
 		3B5A84062569B56F00BAF2E5 /* config.cpp in Sources */ = {isa = PBXBuildFile; fileRef = 3B5A84052569B56F00BAF2E5 /* config.cpp */; };
 		3B5A840D2569BE7C00BAF2E5 /* filesystemImplApple.mm in Sources */ = {isa = PBXBuildFile; fileRef = 3B5A840C2569BE7C00BAF2E5 /* filesystemImplApple.mm */; };
 		3B5A84342569F82C00BAF2E5 /* mkxp.json in CopyFiles */ = {isa = PBXBuildFile; fileRef = 3BD2B7282565B35D003DAD8A /* mkxp.json */; };
@@ -412,7 +411,12 @@
 		3B10EDF32568E96A00372D13 /* module_rpg.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = module_rpg.cpp; sourceTree = "<group>"; };
 		3B10EDF42568E96A00372D13 /* viewport-binding.cpp */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.cpp.cpp; path = "viewport-binding.cpp"; sourceTree = "<group>"; };
 		3B10EE1F2569348E00372D13 /* json5pp.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = json5pp.hpp; sourceTree = "<group>"; };
-		3B426F28256B6C75009EA00F /* libsigc-3.0.a */ = {isa = PBXFileReference; lastKnownFileType = archive.ar; name = "libsigc-3.0.a"; path = "Dependencies/build-macosx-x86_64/lib/libsigc-3.0.a"; sourceTree = "<group>"; };
+		3B426F6B256B8AC0009EA00F /* fs_std_impl.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = fs_std_impl.hpp; sourceTree = "<group>"; };
+		3B426F6C256B8AC0009EA00F /* fs_fwd.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = fs_fwd.hpp; sourceTree = "<group>"; };
+		3B426F6D256B8AC0009EA00F /* fs_std.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = fs_std.hpp; sourceTree = "<group>"; };
+		3B426F6E256B8AC0009EA00F /* filesystem.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = filesystem.hpp; sourceTree = "<group>"; };
+		3B426F6F256B8AC0009EA00F /* fs_impl.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = fs_impl.hpp; sourceTree = "<group>"; };
+		3B426F70256B8AC0009EA00F /* fs_std_fwd.hpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.h; path = fs_std_fwd.hpp; sourceTree = "<group>"; };
 		3B5A84052569B56F00BAF2E5 /* config.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = config.cpp; sourceTree = "<group>"; };
 		3B5A840C2569BE7C00BAF2E5 /* filesystemImplApple.mm */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.objcpp; path = filesystemImplApple.mm; sourceTree = "<group>"; };
 		3B5A84132569C28B00BAF2E5 /* filesystemImpl.cpp */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.cpp.cpp; path = filesystemImpl.cpp; sourceTree = "<group>"; };
@@ -506,7 +510,6 @@
 				3BD2B6ED2565AEC0003DAD8A /* libiconv.tbd in Frameworks */,
 				3BE08105256879FE0006849F /* libvorbisfile.a in Frameworks */,
 				3BE0810E256879FE0006849F /* libSDL2_image.a in Frameworks */,
-				3B426F29256B6C75009EA00F /* libsigc-3.0.a in Frameworks */,
 				3BE0811A256879FE0006849F /* libfreetype.a in Frameworks */,
 				3BE0811D256879FE0006849F /* libphysfs.a in Frameworks */,
 			);
@@ -672,6 +675,7 @@
 		3B10ED522568E95D00372D13 /* filesystem */ = {
 			isa = PBXGroup;
 			children = (
+				3B426F6A256B8AC0009EA00F /* ghc */,
 				3B10ED532568E95D00372D13 /* filesystem.h */,
 				3B10ED542568E95D00372D13 /* filesystem.cpp */,
 				3B5A840C2569BE7C00BAF2E5 /* filesystemImplApple.mm */,
@@ -719,6 +723,7 @@
 		3B10ED6F2568E95D00372D13 /* display */ = {
 			isa = PBXGroup;
 			children = (
+				3B10ED7E2568E95D00372D13 /* gl */,
 				3B10ED702568E95D00372D13 /* tilemap.h */,
 				3B10ED712568E95D00372D13 /* tilemap-common.h */,
 				3B10ED722568E95D00372D13 /* windowvx.cpp */,
@@ -733,7 +738,6 @@
 				3B10ED7B2568E95D00372D13 /* graphics.cpp */,
 				3B10ED7C2568E95D00372D13 /* sprite.h */,
 				3B10ED7D2568E95D00372D13 /* tilemapvx.cpp */,
-				3B10ED7E2568E95D00372D13 /* gl */,
 				3B10ED9A2568E95E00372D13 /* font.h */,
 				3B10ED9B2568E95E00372D13 /* graphics.h */,
 				3B10ED9C2568E95E00372D13 /* tilemap.cpp */,
@@ -821,6 +825,19 @@
 			path = ../binding;
 			sourceTree = "<group>";
 		};
+		3B426F6A256B8AC0009EA00F /* ghc */ = {
+			isa = PBXGroup;
+			children = (
+				3B426F6B256B8AC0009EA00F /* fs_std_impl.hpp */,
+				3B426F6C256B8AC0009EA00F /* fs_fwd.hpp */,
+				3B426F6D256B8AC0009EA00F /* fs_std.hpp */,
+				3B426F6E256B8AC0009EA00F /* filesystem.hpp */,
+				3B426F6F256B8AC0009EA00F /* fs_impl.hpp */,
+				3B426F70256B8AC0009EA00F /* fs_std_fwd.hpp */,
+			);
+			path = ghc;
+			sourceTree = "<group>";
+		};
 		3BA08EA5256641ED00449CFF /* misc */ = {
 			isa = PBXGroup;
 			children = (
@@ -925,7 +942,6 @@
 				3BE081492568A5F60006849F /* libturbojpeg.a */,
 				3BE080FF256879FE0006849F /* libphysfs.a */,
 				3BE080E9256879FC0006849F /* libpixman-1.a */,
-				3B426F28256B6C75009EA00F /* libsigc-3.0.a */,
 				3BE080F4256879FD0006849F /* libruby.2.6-static.a */,
 				3BE080F0256879FD0006849F /* libSDL2_image.a */,
 				3BE080FA256879FE0006849F /* libSDL2_test.a */,
@@ -1443,7 +1459,7 @@
 					"$(DEPENDENCY_SEARCH_PATH)/include",
 					"$(DEPENDENCY_SEARCH_PATH)/lib/**",
 					"$(DEPENDENCY_SEARCH_PATH)/include/SDL2",
-					"$(DEPENDENCY_SEARCH_PATH)/include/sigc++-3.0",
+					"$(DEPENDENCY_SEARCH_PATH)/include/sigc++-2.0",
 					"$(DEPENDENCY_SEARCH_PATH)/include/pixman-1",
 					"$(DEPENDENCY_SEARCH_PATH)/include/ruby-$(MRI_VERSION)",
 					"$(DEPENDENCY_SEARCH_PATH)/include/ruby-$(MRI_VERSION)/$(BUILD_ARCH)-darwin",
@@ -1477,7 +1493,7 @@
 					"$(DEPENDENCY_SEARCH_PATH)/include",
 					"$(DEPENDENCY_SEARCH_PATH)/lib/**",
 					"$(DEPENDENCY_SEARCH_PATH)/include/SDL2",
-					"$(DEPENDENCY_SEARCH_PATH)/include/sigc++-3.0",
+					"$(DEPENDENCY_SEARCH_PATH)/include/sigc++-2.0",
 					"$(DEPENDENCY_SEARCH_PATH)/include/pixman-1",
 					"$(DEPENDENCY_SEARCH_PATH)/include/ruby-$(MRI_VERSION)",
 					"$(DEPENDENCY_SEARCH_PATH)/include/ruby-$(MRI_VERSION)/$(BUILD_ARCH)-darwin",

meson.build

@@ -121,6 +121,10 @@ if get_option('easypoke') == true and miniffi == true
     global_args += '-DEASY_POKE'
 endif
 
+if get_option('cxx11_experimental') == true
+    global_args += '-DUSE_EXPERIMENTAL_FILESYSTEM'
+endif
+
 if not get_option('console')
     global_args += '-DNO_CONSOLE'
 endif

meson_options.txt

@@ -7,6 +7,7 @@ option('console', type: 'boolean', value: false, description: 'Whether to debug
 option('macos_min_version', type: 'string', value: '', description: 'Minimum macOS system version to support (does not affect dependencies)')
 option('force32', type: 'boolean', value: false, description: 'Force compiler to build a 32-bit executable')
 
+option('cxx11_experimental', type: 'boolean', value: false, description: 'Toggles between using ghc/filesystem or C++11 <experimental/filesystem>')
 option('shared_fluid', type: 'boolean', value: false, description: 'Dynamically link fluidsynth at build time')
 option('cjk_fallback_font', type: 'boolean', value: false, description: 'Use WenQuanYi Micro Hei as the fallback font')
 option('use_miniffi', type: 'boolean', value: true, description: 'Enable MiniFFI Ruby module (Win32API)')

src/filesystem/filesystemImpl.cpp

@@ -7,15 +7,22 @@
 
 #include "filesystemImpl.h"
 #include "util/exception.h"
+#include "util/debugwriter.h"
+
+#ifdef USE_EXPERIMENTAL_FILESYSTEM
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#else
+#include "ghc/filesystem.hpp"
+namespace fs = ghc::filesystem;
+#endif
 
-#include <sys/stat.h>
-#include <unistd.h>
 #include <fstream>
 
 // https://stackoverflow.com/questions/12774207/fastest-way-to-check-if-a-file-exist-using-standard-c-c11-c
 bool filesystemImpl::fileExists(const char *path) {
-    struct stat buffer;   
+    fs::path stdPath(path);
-    return (stat (path, &buffer) == 0); 
+    return (fs::exists(stdPath) && !fs::is_directory(stdPath));
 }
 
 
@@ -35,14 +42,45 @@ std::string filesystemImpl::contentsOfFileAsString(const char *path) {
 
 // chdir and getcwd do not support unicode on Windows
 bool filesystemImpl::setCurrentDirectory(const char *path) {
-    return chdir(path);
+    fs::path stdPath(path);
+    fs::current_path(stdPath);
+    bool ret;
+
+    try {
+        ret = fs::equivalent(fs::current_path(), stdPath);
+    } catch (...) {
+        Debug() << "Failed to check current path." << path;
+        ret = false;
+    }
+    return ret;
 }
 
 std::string filesystemImpl::getCurrentDirectory() {
-    return std::string(getcwd(0,0));
+    std::string ret;
+    try {
+        ret = std::string(fs::current_path().string());
+    } catch (...) {
+        throw new Exception(Exception::MKXPError, "Failed to retrieve current path");
+    }
+    return ret;
 }
 
 
 std::string filesystemImpl::normalizePath(const char *path, bool preferred, bool absolute) {
-    return std::string(path);
+    fs::path stdPath(path);
+    
+    if (!stdPath.is_absolute() && absolute)
+        stdPath = fs::current_path() / stdPath;
+
+    stdPath.lexically_normal();
+    std::string ret(stdPath);
+#ifdef __WINDOWS__
+    if (!preferred) {
+        for (int i = 0; i < ret.length(); i++) {
+            if (ret[i] == '\\')
+                ret[i] = '/';
+        }
+    }
+#endif
+    return ret;
 }

src/filesystem/filesystemImplApple.mm

@@ -1,5 +1,5 @@
 //
-//  filesystemImplApple.m
+//  filesystemImplApple.mm
 //  Player
 //
 //  Created by ゾロアーク on 11/21/20.

src/filesystem/ghc/fs_fwd.hpp

@@ -0,0 +1,38 @@
+//---------------------------------------------------------------------------------------
+//
+// ghc::filesystem - A C++17-like filesystem implementation for C++11/C++14
+//
+//---------------------------------------------------------------------------------------
+//
+// Copyright (c) 2018, Steffen Schümann <s.schuemann@pobox.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+//---------------------------------------------------------------------------------------
+// fs_fwd.hpp - The forwarding header for the header/implementation seperated usage of
+//              ghc::filesystem.
+// This file can be include at any place, where ghc::filesystem api is needed while
+// not bleeding implementation details (e.g. system includes) into the global namespace,
+// as long as one cpp includes fs_impl.hpp to deliver the matching implementations.
+//---------------------------------------------------------------------------------------
+#ifndef GHC_FILESYSTEM_FWD_H
+#define GHC_FILESYSTEM_FWD_H
+#define GHC_FILESYSTEM_FWD
+#include <ghc/filesystem.hpp>
+#endif // GHC_FILESYSTEM_FWD_H

src/filesystem/ghc/fs_impl.hpp

@@ -0,0 +1,35 @@
+//---------------------------------------------------------------------------------------
+//
+// ghc::filesystem - A C++17-like filesystem implementation for C++11/C++14
+//
+//---------------------------------------------------------------------------------------
+//
+// Copyright (c) 2018, Steffen Schümann <s.schuemann@pobox.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+//---------------------------------------------------------------------------------------
+// fs_impl.hpp - The implementation header for the header/implementation seperated usage of
+//               ghc::filesystem.
+// This file can be used to hide the implementation of ghc::filesystem into a single cpp.
+// The cpp has to include this before including fs_fwd.hpp directly or via a different
+// header to work.
+//---------------------------------------------------------------------------------------
+#define GHC_FILESYSTEM_IMPLEMENTATION
+#include <ghc/filesystem.hpp>

src/filesystem/ghc/fs_std.hpp

@@ -0,0 +1,56 @@
+//---------------------------------------------------------------------------------------
+//
+// ghc::filesystem - A C++17-like filesystem implementation for C++11/C++14
+//
+//---------------------------------------------------------------------------------------
+//
+// Copyright (c) 2018, Steffen Schümann <s.schuemann@pobox.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+//---------------------------------------------------------------------------------------
+// fs_std.hpp - The dynamic switching header that includes std::filesystem if detected
+//              or ghc::filesystem if not, and makes the resulting API available in the
+//              namespace fs.
+//---------------------------------------------------------------------------------------
+#ifndef GHC_FILESYSTEM_STD_H
+#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || (defined(__cplusplus) && __cplusplus >= 201703L)) && defined(__has_include)
+#if __has_include(<filesystem>) && (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101500)
+#define GHC_USE_STD_FS
+#include <filesystem>
+namespace fs {
+using namespace std::filesystem;
+using ifstream = std::ifstream;
+using ofstream = std::ofstream;
+using fstream = std::fstream;
+}
+#endif
+#endif
+#ifndef GHC_USE_STD_FS
+#define GHC_WIN_WSTRING_STRING_TYPE
+#include <ghc/filesystem.hpp>
+namespace fs {
+using namespace ghc::filesystem;
+using ifstream = ghc::filesystem::ifstream;
+using ofstream = ghc::filesystem::ofstream;
+using fstream = ghc::filesystem::fstream;
+} 
+#endif
+#endif // GHC_FILESYSTEM_STD_H
+

src/filesystem/ghc/fs_std_fwd.hpp

@@ -0,0 +1,60 @@
+//---------------------------------------------------------------------------------------
+//
+// ghc::filesystem - A C++17-like filesystem implementation for C++11/C++14
+//
+//---------------------------------------------------------------------------------------
+//
+// Copyright (c) 2018, Steffen Schümann <s.schuemann@pobox.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+//---------------------------------------------------------------------------------------
+// fs_std_fwd.hpp - The forwarding header for the header/implementation seperated usage of
+//                  ghc::filesystem that uses std::filesystem if it detects it.
+// This file can be include at any place, where fs::filesystem api is needed while
+// not bleeding implementation details (e.g. system includes) into the global namespace,
+// as long as one cpp includes fs_std_impl.hpp to deliver the matching implementations.
+//---------------------------------------------------------------------------------------
+#ifndef GHC_FILESYSTEM_STD_FWD_H
+#define GHC_FILESYSTEM_STD_FWD_H
+#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || (defined(__cplusplus) && __cplusplus >= 201703L)) && defined(__has_include)
+#if __has_include(<filesystem>) && (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101500)
+#define GHC_USE_STD_FS
+#include <filesystem>
+namespace fs {
+using namespace std::filesystem;
+using ifstream = std::ifstream;
+using ofstream = std::ofstream;
+using fstream = std::fstream;
+}
+#endif
+#endif
+#ifndef GHC_USE_STD_FS
+#define GHC_WIN_WSTRING_STRING_TYPE
+#define GHC_FILESYSTEM_FWD
+#include <ghc/filesystem.hpp>
+namespace fs {
+using namespace ghc::filesystem;
+using ifstream = ghc::filesystem::ifstream;
+using ofstream = ghc::filesystem::ofstream;
+using fstream = ghc::filesystem::fstream;
+} 
+#endif
+#endif // GHC_FILESYSTEM_STD_FWD_H
+

src/filesystem/ghc/fs_std_impl.hpp

@@ -0,0 +1,43 @@
+//---------------------------------------------------------------------------------------
+//
+// ghc::filesystem - A C++17-like filesystem implementation for C++11/C++14
+//
+//---------------------------------------------------------------------------------------
+//
+// Copyright (c) 2018, Steffen Schümann <s.schuemann@pobox.com>
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy
+// of this software and associated documentation files (the "Software"), to deal
+// in the Software without restriction, including without limitation the rights
+// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+// copies of the Software, and to permit persons to whom the Software is
+// furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all
+// copies or substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+// SOFTWARE.
+//
+//---------------------------------------------------------------------------------------
+// fs_std_impl.hpp - The implementation header for the header/implementation seperated usage of
+//                   ghc::filesystem that does nothing if std::filesystem is detected.
+// This file can be used to hide the implementation of ghc::filesystem into a single cpp.
+// The cpp has to include this before including fs_std_fwd.hpp directly or via a different
+// header to work.
+//---------------------------------------------------------------------------------------
+#if ((defined(_MSVC_LANG) && _MSVC_LANG >= 201703L) || (defined(__cplusplus) && __cplusplus >= 201703L)) && defined(__has_include)
+#if __has_include(<filesystem>) && (!defined(__MAC_OS_X_VERSION_MIN_REQUIRED) || __MAC_OS_X_VERSION_MIN_REQUIRED >= 101500)
+#define GHC_USE_STD_FS
+#endif
+#endif
+#ifndef GHC_USE_STD_FS
+#define GHC_WIN_WSTRING_STRING_TYPE
+#define GHC_FILESYSTEM_IMPLEMENTATION
+#include <ghc/filesystem.hpp>
+#endif

src/meson.build

@@ -42,7 +42,7 @@ global_include_dirs += include_directories('.',
     'crypto',
     'display', 'display/gl',
     'etc',
-    'filesystem',
+    'filesystem', 'filesystem/ghc',
     'input',
     'system',
     'util'