This is similar to http://www.netbeans.org/issues/show_bug.cgi?id=76032
The root of the evil is absence of functions canonical signatures.
In the example below, within the operator string definition,
code model can not find context,
because it is declared as operator std::string, and defined as operator string()

#include <string>
using namespace std;

class UpdateQuery {
    string table;
    operator std::string() const;
};

UpdateQuery::operator string() const {
    string q = "UPDATE " + table + " SET "; // table unresolved
    return q;                               // code model can not fund context
}