diff options
Diffstat (limited to 'boost/functional/hash/hash.hpp')
| -rw-r--r-- | boost/functional/hash/hash.hpp | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/boost/functional/hash/hash.hpp b/boost/functional/hash/hash.hpp index 2fb9f21116..0a8ceeb474 100644 --- a/boost/functional/hash/hash.hpp +++ b/boost/functional/hash/hash.hpp @@ -212,7 +212,6 @@ namespace boost seed ^= value + 0x9e3779b9 + (seed<<6) + (seed>>2); } - template <typename SizeT> inline void hash_combine_impl(boost::uint32_t& h1, boost::uint32_t k1) { @@ -229,12 +228,11 @@ namespace boost } -// Don't define 64-bit hash combine on platforms with 64 bit integers, +// Don't define 64-bit hash combine on platforms without 64 bit integers, // and also not for 32-bit gcc as it warns about the 64-bit constant. #if !defined(BOOST_NO_INT64_T) && \ !(defined(__GNUC__) && ULONG_MAX == 0xffffffff) - template <typename SizeT> inline void hash_combine_impl(boost::uint64_t& h, boost::uint64_t k) { @@ -247,6 +245,10 @@ namespace boost h ^= k; h *= m; + + // Completely arbitrary number, to prevent 0's + // from hashing to 0. + h += 0xe6546b64; } #endif // BOOST_NO_INT64_T |