It has been reported that compiling a Qt based project with current gcc from svn (upcoming 2.7) fails with
error: inconsistent user-defined literal suffixes '_FILE_' and 'QTOSTRING' in string literal
The problematic line is e.g.
- define QLOCATION "\0"_FILE":"QTOSTRING(LINE_)
so _FILE_ can be interpreted as an string literal suffix of the new user defined literals before it is expanded as macro.