message: feature-testing for remove_cvref, resolves
diff: #pragma once
  +#if THRUST_CPP_DIALECT >= 2017
  +#if __has_include(<version>)
  +# include <version>
  +#endif
  +#endif
  +
  #include <thrust/detail/config.h>
  #include <thrust/detail/type_traits.h>
  namespace thrust
  {
  -#if THRUST_CPP_DIALECT >= 2020
  +#if defined(__cpp_lib_remove_cvref) && (__cpp_lib_remove_cvref >= 201711L)
  using std::remove_cvref;
  using std::remove_cvref_t;
  