From 58e8ae5605abefd0f579586a890dc13fb381b2a3 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Fri, 28 Jan 2022 10:48:49 +0100
Subject: QFlatMap: fix is_transparent detection
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Add a level of indirection via void_t such that

    struct is_transparent {};

works, and not just

    using is_transparent = <unspecified>;

Pick-to: 6.3
Change-Id: I3ca2af6a07e6989dc95abc10fb2d0078a5269e5b
Reviewed-by: Jörg Bornemann <joerg.bornemann@qt.io>
---
 src/corelib/tools/qflatmap_p.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

(limited to 'src/corelib/tools/qflatmap_p.h')

diff --git a/src/corelib/tools/qflatmap_p.h b/src/corelib/tools/qflatmap_p.h
index 512dfa4ae7..77864babc3 100644
--- a/src/corelib/tools/qflatmap_p.h
+++ b/src/corelib/tools/qflatmap_p.h
@@ -417,7 +417,7 @@ private:
     struct is_marked_transparent_type : std::false_type { };
 
     template <class X>
-    struct is_marked_transparent_type<X, typename X::is_transparent> : std::true_type { };
+    struct is_marked_transparent_type<X, std::void_t<typename X::is_transparent>> : std::true_type { };
 
     template <class X>
     using is_marked_transparent = typename std::enable_if<
-- 
cgit v1.2.3