File liborcus-filesystem.patch of Package liborcus

--- liborcus-0.18.1/configure.ac	2023-08-11 00:01:13.087681555 +0200
+++ liborcus-0.18.1/configure.ac	2023-08-11 00:01:22.964416039 +0200
@@ -26,7 +26,7 @@
 AM_INIT_AUTOMAKE([1.11 foreign dist-bzip2 dist-xz])
 AM_SILENT_RULES([yes])
 AC_LANG([C++])
-AX_CXX_COMPILE_STDCXX_17([noext], [mandatory])
+AX_CXX_COMPILE_STDCXX_17([ext], [optional])
 CXXFLAGS="-fvisibility=hidden $CXXFLAGS -Wall -pthread -Wshadow"
 
 # ===========================
@@ -44,6 +44,17 @@
 # =====================
 AC_CHECK_HEADERS([stdlib.h sys/time.h unistd.h])
 
+AC_CHECK_HEADER([filesystem], [ 
+    AC_DEFINE(HAVE_FILESYSTEM, 1, [Define if <filesystem> is present])
+    std_filesystem=yes], [std_filesystem=no], [])
+
+AC_CHECK_HEADER([experimental/filesystem], [
+    AC_DEFINE(HAVE_EXPERIMENTAL_FILESYSTEM, 1, [Define if <experimental/filesystem> is present])
+    experimental_filesystem=yes], [experimental_filesystem=no], [])
+
+AM_CONDITIONAL([STD_FILESYSTEM], [test "x$std_filesystem" = "xyes"])
+AM_CONDITIONAL([EXPERIMENTAL_FILESYSTEM], [test "x$experimental_filesystem" = "xyes"])
+
 # =============================================================
 # Checks for typedefs, structures, and compiler characteristics
 # =============================================================
--- liborcus-0.18.1/doc_example/Makefile.am	2023-08-11 00:01:13.101014980 +0200
+++ liborcus-0.18.1/doc_example/Makefile.am	2023-08-11 00:02:00.191338354 +0200
@@ -91,6 +91,24 @@
 	../src/parser/liborcus-parser-@ORCUS_API_VERSION@.la \
 	../src/liborcus/liborcus-@ORCUS_API_VERSION@.la
 
+if !STD_FILESYSTEM
+if EXPERIMENTAL_FILESYSTEM
+spreadsheet_doc_1_LDADD += -lstdc++fs
+spreadsheet_doc_1_num_and_formula_LDADD += -lstdc++fs
+spreadsheet_doc_2_LDADD += -lstdc++fs
+spreadsheet_doc_2_sheets_no_string_pool_LDADD += -lstdc++fs
+spreadsheet_doc_2_sheets_with_string_pool_LDADD += -lstdc++fs
+spreadsheet_doc_2_sheets_with_formula_LDADD += -lstdc++fs
+else
+spreadsheet_doc_1_LDADD += $(BOOST_FILESYSTEM_LIBS)
+spreadsheet_doc_1_num_and_formula_LDADD += $(BOOST_FILESYSTEM_LIBS)
+spreadsheet_doc_2_LDADD += $(BOOST_FILESYSTEM_LIBS)
+spreadsheet_doc_2_sheets_no_string_pool_LDADD += $(BOOST_FILESYSTEM_LIBS)
+spreadsheet_doc_2_sheets_with_string_pool_LDADD += $(BOOST_FILESYSTEM_LIBS)
+spreadsheet_doc_2_sheets_with_formula_LDADD += $(BOOST_FILESYSTEM_LIBS)
+endif
+endif
+
 AM_TESTS_ENVIRONMENT = \
 	INPUTDIR=$(srcdir)/files; export INPUTDIR;
 
--- liborcus-0.18.1/doc_example/spreadsheet_doc_1.cpp	2023-08-11 00:01:13.101014980 +0200
+++ liborcus-0.18.1/doc_example/spreadsheet_doc_1.cpp	2023-08-11 00:01:22.964416039 +0200
@@ -1,3 +1,6 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
 
 #include <orcus/spreadsheet/document.hpp>
 #include <orcus/spreadsheet/factory.hpp>
@@ -8,13 +11,24 @@
 
 #include <iostream>
 #include <cstdlib>
+#ifdef HAVE_FILESYSTEM
 #include <filesystem>
+namespace fs = std::filesystem;
+#else
+#ifdef HAVE_EXPERIMENTAL_FILESYSTEM
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#else
+#include <boost/filesystem.hpp>
+namespace fs = boost::filesystem;
+#endif
+#endif
 
 using namespace orcus;
 
 int main()
 {
-    std::filesystem::path input_dir = std::getenv("INPUTDIR");
+    fs::path input_dir = std::getenv("INPUTDIR");
 
     //!code-start: instantiate
     spreadsheet::range_size_t ss{1048576, 16384};
--- liborcus-0.18.1/doc_example/spreadsheet_doc_1_num_and_formula.cpp	2023-08-11 00:01:13.101014980 +0200
+++ liborcus-0.18.1/doc_example/spreadsheet_doc_1_num_and_formula.cpp	2023-08-11 00:01:22.964416039 +0200
@@ -1,3 +1,6 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
 
 #include <orcus/spreadsheet/document.hpp>
 #include <orcus/spreadsheet/factory.hpp>
@@ -9,13 +12,24 @@
 #include <ixion/cell.hpp>
 
 #include <iostream>
+#ifdef HAVE_FILESYSTEM
 #include <filesystem>
+namespace fs = std::filesystem;
+#else
+#ifdef HAVE_EXPERIMENTAL_FILESYSTEM
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#else
+#include <boost/filesystem.hpp>
+namespace fs = boost::filesystem;
+#endif
+#endif
 
 using namespace orcus;
 
 int main()
 {
-    std::filesystem::path input_dir = std::getenv("INPUTDIR");
+    fs::path input_dir = std::getenv("INPUTDIR");
 
     // Instantiate a document, and wrap it with a factory.
     spreadsheet::range_size_t ss{1048576, 16384};
--- liborcus-0.18.1/doc_example/spreadsheet_doc_2.cpp	2023-08-11 00:01:13.101014980 +0200
+++ liborcus-0.18.1/doc_example/spreadsheet_doc_2.cpp	2023-08-11 00:01:22.964416039 +0200
@@ -1,8 +1,22 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
 
 #include <orcus/spreadsheet/import_interface.hpp>
 #include <orcus/orcus_ods.hpp>
 
+#ifdef HAVE_FILESYSTEM
 #include <filesystem>
+namespace fs = std::filesystem;
+#else
+#ifdef HAVE_EXPERIMENTAL_FILESYSTEM
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#else
+#include <boost/filesystem.hpp>
+namespace fs = boost::filesystem;
+#endif
+#endif
 #include <iostream>
 
 namespace ss = orcus::spreadsheet;
@@ -33,7 +47,7 @@
 
 int main()
 {
-    std::filesystem::path input_dir = std::getenv("INPUTDIR");
+    fs::path input_dir = std::getenv("INPUTDIR");
     auto filepath = input_dir / "multi-sheets.ods";
 
     my_empty_import_factory factory;
--- liborcus-0.18.1/doc_example/spreadsheet_doc_2_sheets_no_string_pool.cpp	2023-08-11 00:01:13.097681623 +0200
+++ liborcus-0.18.1/doc_example/spreadsheet_doc_2_sheets_no_string_pool.cpp	2023-08-11 00:01:22.964416039 +0200
@@ -1,10 +1,24 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
 
 #include <orcus/spreadsheet/import_interface.hpp>
 #include <orcus/orcus_ods.hpp>
 
 #include <iostream>
 #include <memory>
+#ifdef HAVE_FILESYSTEM
 #include <filesystem>
+namespace fs = std::filesystem;
+#else
+#ifdef HAVE_EXPERIMENTAL_FILESYSTEM
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#else
+#include <boost/filesystem.hpp>
+namespace fs = boost::filesystem;
+#endif
+#endif
 
 //!code-start: cell_value
 namespace ss = orcus::spreadsheet;
@@ -112,7 +126,7 @@
 
 int main()
 {
-    std::filesystem::path input_dir = std::getenv("INPUTDIR");
+    fs::path input_dir = std::getenv("INPUTDIR");
     auto filepath = input_dir / "multi-sheets.ods";
 
     my_import_factory factory;
--- liborcus-0.18.1/doc_example/spreadsheet_doc_2_sheets_with_formula.cpp	2023-08-11 00:01:13.101014980 +0200
+++ liborcus-0.18.1/doc_example/spreadsheet_doc_2_sheets_with_formula.cpp	2023-08-11 00:01:22.964416039 +0200
@@ -1,3 +1,6 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
 
 #include <orcus/spreadsheet/import_interface.hpp>
 #include <orcus/orcus_ods.hpp>
@@ -6,7 +9,18 @@
 #include <memory>
 #include <unordered_map>
 #include <deque>
+#ifdef HAVE_FILESYSTEM
 #include <filesystem>
+namespace fs = std::filesystem;
+#else
+#ifdef HAVE_EXPERIMENTAL_FILESYSTEM
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#else
+#include <boost/filesystem.hpp>
+namespace fs = boost::filesystem;
+#endif
+#endif
 
 namespace ss = orcus::spreadsheet;
 
@@ -279,7 +293,7 @@
 
 int main()
 {
-    std::filesystem::path input_dir = std::getenv("INPUTDIR");
+    fs::path input_dir = std::getenv("INPUTDIR");
     auto filepath = input_dir / "multi-sheets.ods";
 
     my_import_factory factory;
--- liborcus-0.18.1/doc_example/spreadsheet_doc_2_sheets_with_string_pool.cpp	2023-08-11 00:01:13.101014980 +0200
+++ liborcus-0.18.1/doc_example/spreadsheet_doc_2_sheets_with_string_pool.cpp	2023-08-11 00:01:22.964416039 +0200
@@ -1,3 +1,6 @@
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
 
 #include <orcus/spreadsheet/import_interface.hpp>
 #include <orcus/orcus_ods.hpp>
@@ -6,7 +9,18 @@
 #include <memory>
 #include <unordered_map>
 #include <deque>
+#ifdef HAVE_FILESYSTEM
 #include <filesystem>
+namespace fs = std::filesystem;
+#else
+#ifdef HAVE_EXPERIMENTAL_FILESYSTEM
+#include <experimental/filesystem>
+namespace fs = std::experimental::filesystem;
+#else
+#include <boost/filesystem.hpp>
+namespace fs = boost::filesystem;
+#endif
+#endif
 
 namespace ss = orcus::spreadsheet;
 
@@ -193,7 +207,7 @@
 
 int main()
 {
-    std::filesystem::path input_dir = std::getenv("INPUTDIR");
+    fs::path input_dir = std::getenv("INPUTDIR");
     auto filepath = input_dir / "multi-sheets.ods";
 
     my_import_factory factory;
Only in liborcus-0.18.1: liborcus-filesystem.patch