Hello List, Code: boost::xpressive::sregex character = +_w; Dies with compiler error: /usr/include/boost/xpressive/proto/make_expr.hpp:832: error: expected nested-name-specifier before numeric constant /usr/include/boost/xpressive/proto/make_expr.hpp:832: error: expected ‘>’ before numeric constant /usr/include/boost/xpressive/proto/make_expr.hpp:837: error: type/value mismatch at argument 3 in template parameter list for ‘template<class Tag, class DomainOrA0, class A0, class A1, class A2, class A3, class A4, class Void> struct boost::proto::result_of::make_expr’ /usr/include/boost/xpressive/proto/make_expr.hpp:837: error: expected a type, got ‘0’ /usr/include/boost/xpressive/proto/make_expr.hpp:837: error: expected initializer before ‘const’ It does not matter what the expression is. Any idea why xpressive is not working? Thank you, Etienne