Merge pull request #6 from saxbophone/josh/header-only

Switched project to strictly header-only:

Author: saxbophone

tests/CMakeLists.txt

@@ -37,7 +37,7 @@ unset(flag_supported CACHE)
 target_link_libraries(
     tests
     PRIVATE
-        unmoving-compiler-options  # tests use same compiler options as main project
+        unmoving-compiler-options  # use custom compiler options
         unmoving
         Catch2::Catch2             # unit testing framework
 )

unmoving/CMakeLists.txt

@@ -1,42 +1,19 @@
 include(GNUInstallDirs)
 
-add_library(unmoving STATIC)
+add_library(unmoving INTERFACE)  # use INTERFACE for a header-only library
 # ALIAS target to export a namespaced target even when building in-tree
 add_library(Unmoving::unmoving ALIAS unmoving)
-# add source files
-add_subdirectory(src)
 # library public header files location
 target_include_directories(
-    unmoving PUBLIC
+    unmoving INTERFACE
     # different include directory path depending on if using the local or installed version of library
     $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
     $<INSTALL_INTERFACE:${CMAKE_INSTALL_INCLUDEDIR}>
 )
-# pass in version of project as preprocessor definitions
-target_compile_definitions(
-    unmoving PRIVATE
-    -DUNMOVING_VERSION_MAJOR=${PROJECT_VERSION_MAJOR}
-    -DUNMOVING_VERSION_MINOR=${PROJECT_VERSION_MINOR}
-    -DUNMOVING_VERSION_PATCH=${PROJECT_VERSION_PATCH}
-    -DUNMOVING_VERSION_STRING=${UNMOVING_ESCAPED_VERSION_STRING}
-)
-# set up version and soversion for the main library object
-set_target_properties(
-    unmoving PROPERTIES
-    VERSION ${UNMOVING_VERSION_STRING}
-    SOVERSION ${PROJECT_VERSION_MAJOR}
-    INTERFACE_unmoving_MAJOR_VERSION ${PROJECT_VERSION_MAJOR}
-    INTERFACE_unmoving_MINOR_VERSION ${PROJECT_VERSION_MINOR}
-)
+# not 100% sure if this is still needed, but it appears in the package-config output so best to keep
 set_property(
     TARGET unmoving
-    APPEND PROPERTY COMPATIBLE_INTERFACE_STRING "${Unmoving_MAJOR_VERSION}.${Unmoving_MINOR_VERSION}"
-)
-# inherit common project compiler options
-target_link_libraries(
-    unmoving
-        PRIVATE
-            $<BUILD_INTERFACE:unmoving-compiler-options>
+    APPEND PROPERTY COMPATIBLE_INTERFACE_STRING "${PROJECT_VERSION_MAJOR}.${PROJECT_VERSION_MINOR}"
 )
 
 # install if we're not being built as a sub-project