private static void ErrorIfLinesWith( string _Source, string _Pattern )
{
int MatchIndex = _Source.IndexOf( _Pattern, StringComparison.InvariantCultureIgnoreCase );
if ( MatchIndex == -1 )
return; // We're safe!
throw new ConverterException( "Found an unsupported preprocess #if! Please remove the concerned block...", _Source, MatchIndex );
}