I'm trying to compare two tuple instances of the same type (indirectly by doing an == on std::set's of them), but this doesn't compile for me. The Tuple doc seems to indicate comparisons are supported. What am I missing? Thanks, --DD struct RowidTupleComparator { bool operator()( const boost::tuple& lhs, const boost::tuple& rhs ) const { return boost::get<0>(lhs) < boost::get<0>(rhs); } }; void TypeIdTests::test_rtti_vtable_text_vs_int() { typedef boost::tuple ROW; std::set by_type_id; get_rows( "select rowid from rtti where type_id = :1", make_tuple(MyFoo::id().value()), by_type_id ); std::set by_type; get_rows( "select rowid from rtti where type = :1", make_tuple(MyFoo::id().name().string()), by_type ); CPPUNIT_ASSERT_EQUAL(by_type_id.size(), by_type.size()); CPPUNIT_ASSERT(by_type_id == by_type); // <<< doesn't compile } c:\program files\microsoft visual studio 8\vc\include\utility(60) : see declaration of 'std::operator ==' c:\program files\microsoft visual studio 8\vc\include\xutility(2621) : error C2676: binary '==' : 'const boost::tuples::tuple' does not define this operator or a conversion to a type acceptable to the predefined operator // edited