Please, consider applying the following patch to allow empty values in a key/value query string. There are many situations in which they can occur.

Regards,
F. Moya

diff --git a/boost/network/uri/accessors.hpp b/boost/network/uri/accessors.hppindex c050458..5248b34 100644--- a/boost/network/uri/accessors.hpp+++ b/boost/network/uri/accessors.hpp@@ -27,7 +27,7 @@ struct key_value_sequence : spirit::qi::grammar {     pair = key >> -('=' >> value);     key =         spirit::qi::char_("a-zA-Z_") >> *spirit::qi::char_("-+.~a-zA-Z_0-9/%");-    value = +spirit::qi::char_("-+.~a-zA-Z_0-9/%");+    value = *spirit::qi::char_("-+.~a-zA-Z_0-9/%");   }    spirit::qi::rule query;