Rework as esp-idf component

CMakeLists.txt

@@ -2,6 +2,8 @@
 # Distributed under the Boost Software License, Version 1.0.
 # (http://www.boost.org/LICENSE_1_0.txt)
 
+if(NOT DEFINED IDF_TARGET)
+
 cmake_minimum_required(VERSION 3.5...3.20)
 
 project(boost_io VERSION "${BOOST_SUPERPROJECT_VERSION}" LANGUAGES CXX)
@@ -15,3 +17,14 @@ target_link_libraries(boost_io
   INTERFACE
     Boost::config
 )
+
+else()
+
+idf_component_register(
+    INCLUDE_DIRS
+        include
+    REQUIRES
+        boost_config
+)
+
+endif()