[#hash_traits]
== Hash Traits

:idprefix: hash_traits_

=== `<boost/unordered/hash_traits.hpp>` Synopsis

[listing,subs="+macros,+quotes"]
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#include <boost/container_hash/hash_is_avalanching.hpp>

namespace boost {
namespace unordered {

using boost::hash_is_avalanching;

} // namespace unordered
} // namespace boost
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Note:;; This header is deprecated. Use instead
`link:../../../../../container_hash/doc/html/hash.html#ref_hash_is_avalanchinghash[boost::hash_is_avalanching]`
defined in
`link:../../../../../container_hash/doc/html/hash.html#ref_boostcontainer_hashhash_is_avalanching_hpp[<boost/container_hash/hash_is_avalanching.hpp>]`.

Open-addressing and concurrent containers
use the provided hash function `Hash` as-is if `hash_is_avalanching<Hash>::value` is `true`; otherwise, they
implement a bit-mixing post-processing stage to increase the quality of hashing at the expense of
extra computational cost.

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