From 754bb26ffd39e234005cb245174ef87af8a53685 Mon Sep 17 00:00:00 2001
From: Nathan Sashihara <21227491+n8sh@users.noreply.github.com>
Date: Mon, 8 Apr 2019 07:58:38 -0400
Subject: [PATCH] hashmap: increase hashing speed with integer or string keys

TypeInfo.getHash is a virtual function call that is opaque to current
D compilers. Directly using object.hashOf is faster.
---
 utils/vibe/utils/hashmap.d | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/utils/vibe/utils/hashmap.d b/utils/vibe/utils/hashmap.d
index ca8bc5db77..e5f94203fe 100644
--- a/utils/vibe/utils/hashmap.d
+++ b/utils/vibe/utils/hashmap.d
@@ -28,6 +28,10 @@ struct DefaultHashMapTraits(Key) {
 			return () @trusted { return (cast(Key)k).toHash(); } ();
 		else static if (__traits(compiles, Key.init.toHashShared()))
 			return k.toHashShared();
+		else static if ((__traits(isScalar, Key) ||
+				(isArray!Key && is(Key : E[], E) && __traits(isScalar, E))) &&
+				is(typeof((in Key x) @nogc nothrow pure @safe => .object.hashOf(x))))
+			return .object.hashOf(k);
 		else {
 			// evil casts to be able to get the most basic operations of
 			// HashMap nothrow and @nogc