From 52c536bb8d90cf0f09e13f5e9e21bf489cc08c23 Mon Sep 17 00:00:00 2001
From: Chun-wei Fan <fanchunwei@src.gnome.org>
Date: Thu, 10 Feb 2022 16:39:40 +0800
Subject: [PATCH] hb-algs.hh: Fix build on Visual Studio 2015

The compiler does not recognize the std::hash call on
hb_decay<decltype (hb_deref (v)>, so give it a shove so that it is recognized
there.
---
 src/hb-algs.hh | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/hb-algs.hh b/src/hb-algs.hh
index 3a3ab0804..550b8a41a 100644
--- a/src/hb-algs.hh
+++ b/src/hb-algs.hh
@@ -226,8 +226,14 @@ struct
   template <typename T> constexpr auto
   impl (const T& v, hb_priority<2>) const HB_RETURN (uint32_t, hb_deref (v).hash ())
 
+/* Sadly, we must give further hints to VS2015 to build the following template item */
+#if !defined (_MSC_VER) || defined (__clang__) || (_MSC_VER >= 1910)
   template <typename T> constexpr auto
   impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, std::hash<hb_decay<decltype (hb_deref (v))>>{} (hb_deref (v)))
+#else
+  template <typename T> constexpr auto
+  impl (const T& v, hb_priority<1>) const HB_RETURN (uint32_t, std::hash<hb_decay<decltype (hb_deref (v).hash ())>>{} (hb_deref (v)))
+#endif
 
   template <typename T,
 	    hb_enable_if (std::is_integral<T>::value)> constexpr auto