From 0818896cb656b6c40328d24b087e8cab902d4185 Mon Sep 17 00:00:00 2001
From: Jean Pierre Cimalando <jp-dev@inbox.ru>
Date: Thu, 7 May 2020 09:19:38 +0200
Subject: [PATCH] Hashing function for numbers

---
 src/sfizz/StringViewHelpers.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/sfizz/StringViewHelpers.h b/src/sfizz/StringViewHelpers.h
index 141881a9..2907c6ea 100644
--- a/src/sfizz/StringViewHelpers.h
+++ b/src/sfizz/StringViewHelpers.h
@@ -76,3 +76,15 @@ constexpr uint64_t hashNoAmpersand(absl::string_view s, uint64_t h = Fnv1aBasis)
             : hashNoAmpersand( { s.data() + 1, s.length() - 1 }, (h ^ s.front()) * Fnv1aPrime )
     );
 }
+
+/**
+ * @brief Run-time hashing function for numbers, useful for example to
+ *        create hash functions for keys which depend on numeric values.
+ */
+template <class Int>
+uint64_t hashNumber(Int i, uint64_t h = Fnv1aBasis)
+{
+    static_assert(std::is_arithmetic<Int>::value,
+                  "The hashed object must be of arithmetic type");
+    return hash(absl::string_view(reinterpret_cast<const char*>(&i), sizeof(i)), h);
+}