Expected transform fix (#76, thanks @gogagum)

* Add test.
* Fix.

Author: gogagum

include/nonstd/expected.hpp

@@ -1240,11 +1240,11 @@ nsel_constexpr auto invoke( F && f, Args && ... args )
 }
 
 template< typename F, typename ... Args >
-using invoke_result_nocvref_t = typename std20::remove_cvref< decltype( invoke( std::declval< F >(), std::declval< Args >()... ) ) >::type;
+using invoke_result_nocvref_t = typename std20::remove_cvref< decltype( ::nonstd::expected_lite::detail::invoke( std::declval< F >(), std::declval< Args >()... ) ) >::type;
 
 #if nsel_P2505R >= 5
 template< typename F, typename ... Args >
-using transform_invoke_result_t = typename std::remove_cv< decltype( invoke( std::declval< F >(), std::declval< Args >()... ) ) >::type;
+using transform_invoke_result_t = typename std::remove_cv< decltype( ::nonstd::expected_lite::detail::invoke( std::declval< F >(), std::declval< Args >()... ) ) >::type;
 #else
 template< typename F, typename ... Args >
 using transform_invoke_result_t = invoke_result_nocvref_t

test/expected.t.cpp

@@ -1373,6 +1373,8 @@ CASE( "expected: Allows to transform value" " [monadic p2505r3]" )
         EXPECT( ue.transform( mul2 ).error() == 42 );
     }
 
+    expected<std::vector<int>, int>{std::vector<int>{}}.transform([](const std::vector<int>&) { });
+
 #if nsel_P2505R >= 5
     // R5 changed remove_cvref_t to remove_cv_t in transform/transform_error, which broke data member pointer transforms,
     // because the result type must be a valid expected value type, but expressions with reference types are not.