[gcc r10-10182] libstdc++: Add test for std::cmp_greater

[Jonathan Wakely <redi@gcc.gnu.org>]

https://gcc.gnu.org/g:8bff057048efb3f476d45595a206d82582689efc

commit r10-10182-g8bff057048efb3f476d45595a206d82582689efc
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Tue Oct 5 10:38:03 2021 +0100

    libstdc++: Add test for std::cmp_greater
    
    This was omitted from the commit that added these comparisons.
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/20_util/integer_comparisons/greater.cc: New test.
    
    (cherry picked from commit 824e0855732c601e0866d0e8a9264a85f758213e)

Diff:
---
 .../20_util/integer_comparisons/greater.cc         | 61 ++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/libstdc++-v3/testsuite/20_util/integer_comparisons/greater.cc b/libstdc++-v3/testsuite/20_util/integer_comparisons/greater.cc
new file mode 100644
index 00000000000..e564d8d03f2
--- /dev/null
+++ b/libstdc++-v3/testsuite/20_util/integer_comparisons/greater.cc
@@ -0,0 +1,61 @@
+// { dg-options "-std=gnu++20" }
+// { dg-do run { target c++20 } }
+
+#include <utility>
+#include <limits>
+#include <testsuite_hooks.h>
+
+void
+test01()
+{
+  unsigned int u = std::numeric_limits<unsigned int>::max();
+  int s = -1;
+  VERIFY( !std::cmp_greater(s, u) );
+  VERIFY( std::cmp_greater(u, s) );
+  u = (unsigned) std::numeric_limits<int>::max() + 1U;
+  VERIFY( !std::cmp_greater(s, u) );
+  VERIFY( std::cmp_greater(u, s) );
+}
+
+constexpr bool
+test02()
+{
+  unsigned int u = std::numeric_limits<unsigned int>::max();
+  int s = -1;
+  if (std::cmp_greater(s, u))
+    throw 1;
+  if (!std::cmp_greater(u, s))
+    throw 2;
+  return true;
+}
+
+void
+test03()
+{
+  short ss = -1;
+  int s = -1;
+  VERIFY( !std::cmp_greater(s, ss) );
+  VERIFY( !std::cmp_greater(ss, s) );
+
+  unsigned int u = (unsigned int) -1;
+  VERIFY( !std::cmp_greater(s, u) );
+  VERIFY( std::cmp_greater(u, s) );
+  VERIFY( !std::cmp_greater(ss, u) );
+  VERIFY( std::cmp_greater(u, ss) );
+
+  unsigned long long ul = (unsigned long long) -1;
+  VERIFY( !std::cmp_greater(s, ul) );
+  VERIFY( std::cmp_greater(ul, s) );
+  VERIFY( !std::cmp_greater(ss, ul) );
+  VERIFY( std::cmp_greater(ul, ss) );
+  VERIFY( !std::cmp_greater(u, ul) );
+  VERIFY( std::cmp_greater(ul, u) );
+}
+
+int
+main()
+{
+  test01();
+  static_assert( test02() );
+  test03();
+}