From cb06fb9b296f7cfafc76741013f3f9757a15fd6c Mon Sep 17 00:00:00 2001
From: Danny Robson <danny@nerdcruft.net>
Date: Mon, 24 Jul 2023 12:55:48 +1000
Subject: [PATCH] hash/mix: add a simple std compatible wrapper for hash::mix

---
 CMakeLists.txt |  2 ++
 hash/mix.cpp   |  1 +
 hash/mix.hpp   | 23 +++++++++++++++++++++++
 3 files changed, 26 insertions(+)
 create mode 100644 hash/mix.cpp
 create mode 100644 hash/mix.hpp

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 32532a20..3619bcb4 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -412,6 +412,8 @@ list (
     hash/fnv1a.hpp
     hash/halfsipmix.cpp
     hash/halfsipmix.hpp
+    hash/mix.cpp
+    hash/mix.hpp
     hash/murmur/common.cpp
     hash/murmur/common.hpp
     hash/murmur.hpp
diff --git a/hash/mix.cpp b/hash/mix.cpp
new file mode 100644
index 00000000..0abe4721
--- /dev/null
+++ b/hash/mix.cpp
@@ -0,0 +1 @@
+#include "./mix.hpp"
\ No newline at end of file
diff --git a/hash/mix.hpp b/hash/mix.hpp
new file mode 100644
index 00000000..dc9942a4
--- /dev/null
+++ b/hash/mix.hpp
@@ -0,0 +1,23 @@
+#pragma once
+
+#include "../hash.hpp"
+
+#include <utility>
+
+
+namespace cruft::hash {
+    /// A std compatible adapter for a variadic 'mix' hash.
+    ///
+    /// It combines multiple values in a way that is unlikely to result in collisions.
+    ///
+    /// The exact implementation is not defined.
+    struct mixer {
+        template <typename ...ValueT>
+        auto operator () (ValueT &&...elements)
+        {
+            return cruft::hash::mix (
+                std::forward<ValueT> (elements)...
+            );
+        }
+    };
+}
\ No newline at end of file