Rationale (July, 2009):

This suggestion would need a full proposal and discussion by the EWG before the CWG could consider it.

[Addressed with a different approach by paper P0846R0, adopted at the November, 2017 meeting.]

Consider the following:

    namespace N {
        struct A { };
        template<typename T>
        T func(const A&) { return T(); }
    }

    void f() {
        N::A a;
        func<int>(a);    // error
    }

Although argument-dependent lookup would allow N::func to be found in this call, the < is taken as a less-than operator rather than as the beginning of a template argument list. If the use of the template keyword for syntactic disambiguation were permitted for unqualified-ids, this problem could be solved by prefixing the function name with template, allowing the template-id to be parsed and argument-dependent lookup to be performed.