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/**
* @file llhash.h
* @brief Wrapper for a hash function.
*
* $LicenseInfo:firstyear=2004&license=viewerlgpl$
* Second Life Viewer Source Code
* Copyright (C) 2010, Linden Research, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation;
* version 2.1 of the License only.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*
* Linden Research, Inc., 945 Battery Street, San Francisco, CA 94111 USA
* $/LicenseInfo$
*/
#ifndef LL_LLHASH_H
#define LL_LLHASH_H
#include <boost/functional/hash.hpp>
// Warning - an earlier template-based version of this routine did not do
// the correct thing on Windows. Since this is only used to get
// a string hash, it was converted to a regular routine and
// unit tests added.
inline size_t llhash( const char * value )
{
// boost::hash is defined for std::string and for char, but there's no
// special overload for const char*. The lazy approach would be to
// instantiate a std::string and take its hash, but that might be more
// overhead than our callers want. Or we could use boost::hash_range() --
// but that would require a preliminary pass over the value to determine
// the end iterator. Instead, use boost::hash_combine() to hash individual
// characters.
std::size_t seed = 0;
for ( ; *value; ++value)
boost::hash_combine(seed, *value);
return seed;
}
#endif
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