config.h support removed as it causes issues with compiler-explorer

src/CMakeLists.txt

@@ -34,9 +34,6 @@ list(APPEND CMAKE_MODULE_PATH "${CMAKE_CURRENT_SOURCE_DIR}/../cmake")
 # include common tools and workarounds
 include(common/cmake/tools)
 
-# check availability of C++20 features
-include(check_features)
-
 # library definition
 add_library(units INTERFACE)
 #target_sources(units INTERFACE
@@ -62,7 +59,6 @@ target_link_libraries(units
 target_include_directories(units
     INTERFACE
         $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
-        $<BUILD_INTERFACE:${CMAKE_CURRENT_BINARY_DIR}/include>
         $<INSTALL_INTERFACE:include>
 )
 target_compile_options(units

src/include/units/bits/hacks.h

@@ -22,22 +22,10 @@
 
 #pragma once
 
-#include <units/bits/config.h>
 #include <experimental/ranges/concepts>
 
 namespace std {
 
-#ifndef UNITS_HAS_STD_TYPE_IDENTITY
-
-  // type_identity
-  template<typename T>
-  struct type_identity { using type = T; };
-
-  template<typename T>
-  using type_identity_t = typename type_identity<T>::type;
-
-#endif // UNITS_HAS_STD_TYPE_IDENTITY
-
   // concepts
   using experimental::ranges::same_as;
   using experimental::ranges::derived_from;