[#SaltedOutpointHasher-operator_call]
= xref:SaltedOutpointHasher.adoc[SaltedOutpointHasher]::operator()
:relfileprefix: ../
:mrdocs:

Having the hash noexcept allows libstdc++'s unordered_map to recalculate the hash during rehash, so it does not have to cache the value. This reduces node's memory by sizeof(size_t). The required recalculation has a slight performance penalty (around 1.6%), but this is compensated by memory savings of about 9% which allow for a larger dbcache setting.

== Synopsis

Declared in `<util/hasher.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
size_t
operator()(xref:COutPoint.adoc[COutPoint] const& id) const noexcept;
----

== Return Value

The salted SipHash of the outpoint's hash and index.

== Parameters

[cols="1,4"]
|===
| Name| Description
| *id*
| The outpoint to hash.
|===

== See Also

https://gcc.gnu.org/onlinedocs/gcc‐13.2.0/libstdc++/manual/manual/unordered_associative.html


[.small]#Created with https://www.mrdocs.com[MrDocs]#