From 72140a8583a3b6865e032d891104ef1b029e3c03 Mon Sep 17 00:00:00 2001
From: Eugen Wissner <belka@caraus.de>
Date: Mon, 19 Mar 2018 21:03:22 +0100
Subject: [PATCH] Add documentation for the hash function

---
 source/tanya/hash/lookup.d | 24 +++++++++++++++++++++++-
 1 file changed, 23 insertions(+), 1 deletion(-)

diff --git a/source/tanya/hash/lookup.d b/source/tanya/hash/lookup.d
index 817670b..2ca5b66 100644
--- a/source/tanya/hash/lookup.d
+++ b/source/tanya/hash/lookup.d
@@ -77,7 +77,29 @@ private struct FNV
 }
 
 /**
- * FNV-1a (Fowler-Noll-Vo) hash function.
+ * Takes an a argument of an arbitrary type $(D_PARAM T) and calculates the hash value.
+ *
+ * Hash calculation is supported for all scalar types. Aggregate types, like
+ *$(D_KEYWORD struct)s should implement `toHash`-function:
+ * ---
+ * size_t toHash() const
+ * {
+ *  return hash;
+ * }
+ * ---
+ *
+ * For scalar types FNV-1a (Fowler-Noll-Vo) hash function is used internally.
+ * If the type provides a `toHash`-function, only `toHash()` is called and its
+ * result is returned.
+ *
+ * This function also accepts input ranges that contain hashable elements.
+ * Individual values are combined then and the resulting hash is returned.
+ *
+ * Params:
+ *  T = Hashable type.
+ *  key = Hashable value.
+ *
+ * Returns: Calculated hash value.
  *
  * See_Also: $(LINK http://www.isthe.com/chongo/tech/comp/fnv/).
  */