Make the library header-only in CMakeLists.txt

CMakeLists.txt

@@ -1,3 +1,4 @@
+# Generated by `boostdep --cmake exception`
 # Copyright 2020, 2021 Peter Dimov
 # Distributed under the Boost Software License, Version 1.0.
 # https://www.boost.org/LICENSE_1_0.txt
@@ -6,16 +7,13 @@ cmake_minimum_required(VERSION 3.5...3.20)
 
 project(boost_exception VERSION "${BOOST_SUPERPROJECT_VERSION}" LANGUAGES CXX)
 
-add_library(boost_exception STATIC
-  src/clone_current_exception_non_intrusive.cpp
-)
-
+add_library(boost_exception INTERFACE)
 add_library(Boost::exception ALIAS boost_exception)
 
-target_include_directories(boost_exception PUBLIC include)
+target_include_directories(boost_exception INTERFACE include)
 
 target_link_libraries(boost_exception
-  PUBLIC
+  INTERFACE
     Boost::assert
     Boost::config
     Boost::core