From dd4e96df528a64bd994bf44e9b618463e0562ab0 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@kdab.com>
Date: Fri, 8 May 2020 11:02:58 +0200
Subject: [PATCH] tst_qstringview: modernize functions in help namespace
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They don't work with std::span, since std::span has neither
const_iterator nor cbegin()/cend().

To fix, perfectly forward the return type with decltype(auto) instead
of mentioning T::const_iterator, and rely on the const-qualfication of
the help::c{r,}{begin,end}() functions' arguments to select the
correct T::{r,}{begin,end}() overload.

Change-Id: I4992d4bd521d2dc0f9ea51ae70cde8286ae543a5
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
---
 tests/auto/corelib/text/qstringview/tst_qstringview.cpp | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/tests/auto/corelib/text/qstringview/tst_qstringview.cpp b/tests/auto/corelib/text/qstringview/tst_qstringview.cpp
index 631bcce508..5b9eb03fe3 100644
--- a/tests/auto/corelib/text/qstringview/tst_qstringview.cpp
+++ b/tests/auto/corelib/text/qstringview/tst_qstringview.cpp
@@ -575,22 +575,22 @@ size_t size(const QChar *t)
 }
 
 template <typename T>
-typename T::const_iterator cbegin(const T &t) { return t.cbegin(); }
+decltype(auto)             cbegin(const T &t) { return t.begin(); }
 template <typename T>
 const T *                  cbegin(const T *t) { return t; }
 
 template <typename T>
-typename T::const_iterator cend(const T &t) { return t.cend(); }
+decltype(auto)             cend(const T &t) { return t.end(); }
 template <typename T>
 const T *                  cend(const T *t) { return t + size(t); }
 
 template <typename T>
-typename T::const_reverse_iterator crbegin(const T &t) { return t.crbegin(); }
+decltype(auto)                     crbegin(const T &t) { return t.rbegin(); }
 template <typename T>
 std::reverse_iterator<const T*>    crbegin(const T *t) { return std::reverse_iterator<const T*>(cend(t)); }
 
 template <typename T>
-typename T::const_reverse_iterator crend(const T &t) { return t.crend(); }
+decltype(auto)                     crend(const T &t) { return t.rend(); }
 template <typename T>
 std::reverse_iterator<const T*>    crend(const T *t) { return std::reverse_iterator<const T*>(cbegin(t)); }