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Daniel James

Distributed under the Boost Software License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at

Table of Contents

Extending boost::hash for a custom data type
Combining hash values
Disabling The Extensions
Change Log
Header <boost/functional/hash.hpp>

boost::hash is an implementation of the hash function object specified by the Draft Technical Report on C++ Library Extensions (TR1). It is intended for use as the default hash function for unordered associative containers, and the Boost Multi-Index Containers Library's hash indexes.

As it is compliant with TR1, it will work with:

  • integers
  • floats
  • pointers
  • strings

It also implements the extension proposed by Peter Dimov in issue 6.18 of the Library Extension Technical Report Issues List (page 63), this adds support for:

  • arrays
  • std::pair
  • the standard containers.
  • extending boost::hash for custom types.

Last revised: March 28, 2008 at 08:11:13 GMT