c++/7732: erroneous "implicit typename is deprecated" warning

c++/7732: erroneous "implicit typename is deprecated" warning

[Paul J. Lucas]

>Number:         7732
>Category:       c++
>Synopsis:       g++ issues erroneous warning: implicit typename is deprecated
>Confidential:   no
>Severity:       non-critical
>Priority:       low
>Responsible:    unassigned
>State:          open
>Class:          rejects-legal
>Submitter-Id:   net
>Arrival-Date:   Mon Aug 26 21:16:01 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     Paul J. Lucas
>Release:        3.2
>Organization:
>Environment:
System: Linux powerbook 2.4.18-rc4-benh #1 Mon Feb 25 23:23:12 PST 2002 ppc unknown
Architecture: ppc
host: powerpc-unknown-linux-gnu
build: powerpc-unknown-linux-gnu
target: powerpc-unknown-linux-gnu
configured with: /tmp/gcc-3.2/configure --prefix=/usr/local/packages/gcc-3.2 --enable-threads=posix --enable-languages=c,c++ --disable-nls
>Description:
Compiler issues aforementioned warning regarding result_type and argument_type.
The complete warning is:
----- CUT -----
bug.c:8: warning: `typename pattern_map<T>::pattern_match::result_type' is implicitly a typename
bug.c:8: warning: implicit typename is deprecated, please see the documentation for details
bug.c:8: warning: `typename pattern_map<T>::pattern_match::argument_type' is implicitly a typename
bug.c:8: warning: implicit typename is deprecated, please see the documentation for details
----- CUT -----
Note that this warning is not issued if the class pattern_map is at file scope
and not within a template.
>How-To-Repeat:
Compile this code:
//----- CUT -----
#include <map>

template< class T > struct pattern_map : std::map< int, T > {
	typedef typename std::map< int, T > map_type;
	typedef typename map_type::value_type value_type;

	struct pattern_match : std::unary_function< value_type const&, bool > {
		result_type operator()( argument_type a ) const {
			return true;
		}
	};
};

struct pattern_match : std::unary_function< int, bool > {
	result_type operator()( argument_type a ) const {
		return true;
	}
};

main() {
	pattern_map<int> p;
}
//----- CUT -----
>Fix:

>Release-Note:
>Audit-Trail:
>Unformatted: