From 1b8b8024554f9f36bc6642c2dfe830765e932df5 Mon Sep 17 00:00:00 2001
From: Marc Mutz <marc.mutz@qt.io>
Date: Thu, 9 Jun 2022 09:52:58 +0200
Subject: [PATCH] tst_QAnyStringView: explicitly check the spaceship operator
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We implicitly checked it, because, in C++20 builds, the non-equality
relational operators are synthesized from it by the compiler, and we
test those, but we didn't check that <=> returns strong_ordering.

We now do.

Pick-to: 6.4 6.3 6.2
Task-number: QTBUG-104108
Change-Id: Ieb19a2d4cb2d600d884f4e2e89e98c6187e23872
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Mårten Nordheim <marten.nordheim@qt.io>
---
 .../qanystringview/tst_qanystringview.cpp     | 31 +++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/tests/auto/corelib/text/qanystringview/tst_qanystringview.cpp b/tests/auto/corelib/text/qanystringview/tst_qanystringview.cpp
index fe7083502e..4433b8efbc 100644
--- a/tests/auto/corelib/text/qanystringview/tst_qanystringview.cpp
+++ b/tests/auto/corelib/text/qanystringview/tst_qanystringview.cpp
@@ -42,6 +42,14 @@
 #  define ONLY_WIN(expr) QSKIP("This is a Windows-only test")
 #endif
 
+#ifdef __cpp_impl_three_way_comparison
+#  define ONLY_3WAY(expr) expr
+#else
+#  define ONLY_3WAY(expr) \
+    QSKIP("This test requires C++20 spaceship operator (<=>) " \
+          "support enabled in the standard library.")
+#endif
+
 using namespace Qt::StringLiterals;
 
 template <typename T>
@@ -292,6 +300,7 @@ private Q_SLOTS:
     void fromQStringBuilder_QString_QString() const { fromQStringBuilder(u"1"_s % u"2"_s, u"12"); }
 
     void comparison();
+    void compare3way();
 
 private:
     template <typename StringBuilder>
@@ -629,5 +638,27 @@ void tst_QAnyStringView::comparison()
     QVERIFY(QAnyStringView::compare(bb, aa) > 0);
 }
 
+void tst_QAnyStringView::compare3way()
+{
+#define COMPARE_3WAY(lhs, rhs, res) \
+    do { \
+        const auto qt_3way_cmp_res = (lhs) <=> (rhs); \
+        static_assert(std::is_same_v<decltype(qt_3way_cmp_res), decltype(res)>); \
+        QCOMPARE(std::is_eq(qt_3way_cmp_res), std::is_eq(res)); \
+        QCOMPARE(std::is_lt(qt_3way_cmp_res), std::is_lt(res)); \
+        QCOMPARE(std::is_gt(qt_3way_cmp_res), std::is_gt(res)); \
+    } while (false)
+
+    ONLY_3WAY(
+    const QAnyStringView aa = u"aa";
+    const QAnyStringView upperAa = u"AA";
+    const QAnyStringView bb = u"bb";
+    COMPARE_3WAY(aa, aa, std::strong_ordering::equal);
+    COMPARE_3WAY(aa, bb, std::strong_ordering::less);
+    COMPARE_3WAY(bb, aa, std::strong_ordering::greater)
+    );
+#undef COMPARE_3WAY
+}
+
 QTEST_APPLESS_MAIN(tst_QAnyStringView)
 #include "tst_qanystringview.moc"