Hi Chris, I answer some of my own questions below. Best, Paul On Fri, 19 Aug 2005 10:15 am, Paul C. Leopardi wrote: > It seems that TR1 itself has usability problems with its support for user > defined hash functions for std::tr1::unordered_map< K, T > where K is a > user defined class. See "Library Extension Technical Report Issues List, > Revision 10: June 2005 mid-meeting mailing" N1837, item 6.18 pp. 63--67. > > http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1837.pdf ... > So, it looks to me like there is supposed to be a way for me to write a > user defined hash function, but it is not well enough documented for me to > tell the difference between my own errors and errors in the compiler or the > library. The boost::hash library is an implementation of both TR1 and item 6.18, allowing user defined hash functions. http://boost.org/doc/html/hash.html The boost::hash library documentation also includes exactly the usage example I need to be able to define my own hash functions. http://boost.org/doc/html/hash/custom.html Unfortunately, even when using boost::hash, I still see error messages when compiling. My code now looks like: #include <boost/functional/hash.hpp> #include <tr1/unordered_map> ... template< const glucat::index_t LO, const glucat::index_t HI > inline size_t hash_value(index_set<LO,HI> val) { return val.hash_fn(); }; ... template< typename Scalar_T, const index_t LO = DEFAULT_LO, const index_t HI = DEFAULT_HI > class framed_multi : public clifford_algebra< Scalar_T, index_set<LO,HI>, framed_multi<Scalar_T,LO,HI> >, private std::tr1::unordered_map< index_set<LO,HI>, Scalar_T, boost::hash< index_set<LO,HI> > > { ... int main() { ... typedef framed_multi<double> number; typedef number::index_set_t e; number OP = number(e(1),4.0) + number(e(2),3.0); } and the error message is now usr/local/gcc/gcc-4.0-20050728/lib/gcc/x86_64-suse-linux/4.0.2/../../../../include/c++/4.0.2/tr1/hashtable: In copy constructor ‘std::tr1::hashtable<Key, Value, Allocator, ExtractKey, Equal, H1, H2, H, RehashPolicy, cache_hash_code, mutable_iterators, unique_keys>::hashtable(const std::tr1::hashtable<Key, Value, Allocator, ExtractKey, Equal, H1, H2, H, RehashPolicy, cache_hash_code, mutable_iterators, unique_keys>&) [with Key = glucat::index_set<-0x00000000000000020, 32>, Value = std::pair<const glucat::index_set<-0x00000000000000020, 32>, double>, Allocator = std::allocator<std::pair<const glucat::index_set<-0x00000000000000020, 32>, double> >, ExtractKey = Internal::extract1st<std::pair<const glucat::index_set<-0x00000000000000020, 32>, double> >, Equal = std::equal_to<glucat::index_set<-0x00000000000000020, 32> >, H1 = boost::hash<glucat::index_set<-0x00000000000000020, 32> >, H2 = Internal::mod_range_hashing, H = Internal::default_ranged_hash, RehashPolicy = Internal::prime_rehash_policy, bool cache_hash_code = false, bool mutable_iterators = true, bool unique_keys = true]’: /usr/local/gcc/gcc-4.0-20050728/lib/gcc/x86_64-suse-linux/4.0.2/../../../../include/c++/4.0.2/tr1/unordered_map:59: instantiated from here /usr/local/gcc/gcc-4.0-20050728/lib/gcc/x86_64-suse-linux/4.0.2/../../../../include/c++/4.0.2/tr1/hashtable:1046: error: no matching function for call to ‘std::tr1::hashtable<glucat::index_set<-0x00000000000000020, 32>, std::pair<const glucat::index_set<-0x00000000000000020, 32>, double>, std::allocator<std::pair<const glucat::index_set<-0x00000000000000020, 32>, double> >, Internal::extract1st<std::pair<const glucat::index_set<-0x00000000000000020, 32>, double> >, std::equal_to<glucat::index_set<-0x00000000000000020, 32> >, boost::hash<glucat::index_set<-0x00000000000000020, 32> >, Internal::mod_range_hashing, Internal::default_ranged_hash, Internal::prime_rehash_policy, false, true, true>::m_allocate_node(Internal::hash_node<std::pair<const glucat::index_set<-0x00000000000000020, 32>, double>, false>*&)’ compilation terminated due to -Wfatal-errors. At this point, it looks like a bug in libstdc++ and not a usage error on my part.
