some user experience improvements in alib2str

alib2str/src/registration/StringRegistration.hpp

@@ -39,7 +39,7 @@ public:
 		core::stringApi < Group >::template registerStringReader < Type > ( );
 		abstraction::StringReaderRegistry::registerStringReader < Group, Type > ( );
-		abstraction::AlgorithmRegistry::registerWrapper < string::Parse < Group >, std::string && > ( string::Parse < Group >::abstractionFromString, std::array < std::string, 1 > { } );
+		abstraction::AlgorithmRegistry::registerWrapper < string::Parse < Group >, std::string && > ( string::Parse < Group >::abstractionFromString, std::array < std::string, 1 > { { "arg0" } } );
 	}
 };
@@ -50,7 +50,7 @@ public:
 		core::stringApi < Group >::template registerStringWriter < Type > ( );
 		abstraction::StringWriterRegistry::registerStringWriter < Type > ( );
-		abstraction::AlgorithmRegistry::registerWrapper < string::Compose, const Type & > ( string::Compose::abstractionFromType, std::array < std::string, 1 > { } );
+		abstraction::AlgorithmRegistry::registerWrapper < string::Compose, const Type & > ( string::Compose::abstractionFromType, std::array < std::string, 1 > { { "arg0" } } );
 	}
 };

alib2str/src/registry/StringReaderRegistry.cpp

@@ -19,7 +19,7 @@ std::shared_ptr < abstraction::OperationAbstraction > StringReaderRegistry::getA
 	const auto & entries = getEntries ( ) [ group ];
 	typename ext::deque < std::pair < std::function < bool ( std::istream & ) >, std::unique_ptr < Entry > > >::const_iterator callback = find_if ( entries.begin ( ), entries.end ( ), lambda );
 	if ( callback == entries.end ( ) )
-		throw exception::CommonException ( "Entry not available." );
+		throw exception::CommonException ( "Entry " + group + " not available." );
 	return callback->second->getAbstraction ( );
 }