use std::invoke() vor C++17 onwards

But std::invoke() is defined since C++17.
For pre C++17 use boost::context::detail::invoke() instead.

include/boost/coroutine2/detail/wrap.hpp

@@ -7,10 +7,13 @@
 #ifndef BOOST_COROUTINE2_DETAIL_WRAP_H
 #define BOOST_COROUTINE2_DETAIL_WRAP_H
 
+#include <functional>
 #include <type_traits>
 
 #include <boost/config.hpp>
+#if defined(BOOST_NO_CXX17_STD_INVOKE)
 #include <boost/context/detail/invoke.hpp>
+#endif
 #include <boost/context/fiber.hpp>
 
 #include <boost/coroutine2/detail/config.hpp>
@@ -43,10 +46,17 @@ class wrapper {
 
     boost::context::fiber
     operator()( boost::context::fiber && c) {
+#if defined(BOOST_NO_CXX17_STD_INVOKE)
         return boost::context::detail::invoke(
                 std::move( fn1_),
                 fn2_,
                 std::forward< boost::context::fiber >( c) );
+#else
+        return std::invoke(
+                std::move( fn1_),
+                fn2_,
+                std::forward< boost::context::fiber >( c) );
+#endif
     }
 };