Hi, I have some idea related to the usage of UDLs in Boost.Geometry library but the way I'd like to handle it is AFAIK not supported. A little introduction first. There are many text-based languages of defining data. One of them is WKT (http://en.wikipedia.org/wiki/Well-known_text) which allows to define vector data e.g. a polygon like this: |POLYGON((30 10, 40 40, 20 40, 10 20, 30 10))| So my thought was: why not use C++11 UDLs for this purpose? There are operators in the WKT language so I should probably use string literal, put WKT in it and be happy with it. The use case could look like this: |auto ||polygon = "POLYGON((30 10,40 40,20 40,10 20,30 10))|"_wkt; Ok so now the tricky part. It should be parsed in compile-time, the type of the geometry retrieved from the string literal and proper type returned (bg::polygon<> in this case). Unfortunately string literals can't be handled as raw literals, e.g. using the variadic-template version of operator"": template <char...> void operator "" () Why? Is there a reason for this? If we had the ability to use the compile-time version with string literals it would be possible to implement various compile-time parsers, not only for the mentioned WKT. So what do you think about it? Regards, Adam