Draft: Feat: setup VC environment during configuration

This would allow us to build using ninja from the command line. This is currently not possible as CMake cannot find cl when building from a "normal" shell. The vcvarsall script would have to be called before. This is very inconvenient. With this change the vc environment would be setup during configuration. However, as discussed here this does not work correctly yet.

src/Index.cmake

@@ -68,3 +68,18 @@ macro (find_package)
 	# 	message (FATAL_ERROR "Package ${ARGV0} found as a Target; skip find_package")
 	# endif ()
 endmacro ()
+
+CPMAddPackage (
+	NAME project_options
+	GITHUB_REPOSITORY aminya/project_options
+	VERSION 0.36.4
+	DOWNLOAD_ONLY YES
+)
+
+include (${project_options_SOURCE_DIR}/src/VCEnvironment.cmake)
+
+if ("${CMAKE_TOOLCHAIN_FILE}" STREQUAL "")
+	msvc_toolchain ()
+else ()
+	message (STATUS "project_options: skipping msvc_toolchain as CMAKE_TOOLCHAIN_FILE is set")
+endif ()