Fix compiler errors wrt. USE_BOOST_FILESYSTEM

CMakeLists.txt

@@ -23,7 +23,7 @@ find_package(Boost 1.54.0 COMPONENTS ${USED_BOOST_LIBS} REQUIRED)
 
 add_library(inotify-filesystem-adapter INTERFACE)
 if(CMAKE_CXX_STANDARD LESS 17 OR USE_BOOST_FILESYSTEM)
-    add_definitions(-DUSE_BOOST_FILESYSTEM)
+    target_compile_definitions(inotify-filesystem-adapter INTERFACE USE_BOOST_FILESYSTEM)
     target_link_libraries(inotify-filesystem-adapter INTERFACE Boost::filesystem)
 else()
     target_link_libraries(inotify-filesystem-adapter INTERFACE stdc++fs)

src/CMakeLists.txt

@@ -35,6 +35,9 @@ macro(configure_target target)
                 $<INSTALL_INTERFACE:include>
                 ${Boost_INCLUDE_DIR})
         target_link_libraries(${target} PUBLIC inotify-filesystem-adapter)
+	if(CMAKE_CXX_STANDARD LESS 17 OR USE_BOOST_FILESYSTEM)
+	        target_compile_definitions(${target} PUBLIC USE_BOOST_FILESYSTEM)
+        endif()
 
 endmacro(configure_target target)
 

src/Inotify.cpp

@@ -105,7 +105,11 @@ void Inotify::watchDirectoryRecursively(fs::path path)
         if (fs::is_directory(path)) {
             inotifypp::error_code ec;
             fs::recursive_directory_iterator it(
+              #if !defined USE_BOOST_FILESYSTEM || (defined USE_BOOST_FILESYSTEM && BOOST_VERSION >= 107200)
                 path, fs::directory_options::follow_directory_symlink, ec);
+               #else
+                path, ec);
+               #endif
             fs::recursive_directory_iterator end;
 
             for (; it != end; it.increment(ec)) {

src/include/inotify-cpp/FileSystemAdapter.h

@@ -22,6 +22,7 @@ namespace inotifypp
 
 #include <boost/filesystem.hpp>
 #include <boost/optional.hpp>
+#include <boost/version.hpp>
 
 namespace inotifypp
 {
@@ -32,7 +33,7 @@ namespace inotifypp
     template<typename T>
     using optional = boost::optional<T>;
 
-    inline constexpr boost::none_t nullopt() { return boost::none; };
+    inline boost::none_t nullopt() { return boost::none; };
 }
 
 #endif