[gcc r12-5539] libstdc++: Move std::to_address tests to more appropriate place

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

https://gcc.gnu.org/g:0178b73a02021551f83e3e52c4819c4096513301

commit r12-5539-g0178b73a02021551f83e3e52c4819c4096513301
Author: Jonathan Wakely <jwakely@redhat.com>
Date:   Fri Nov 26 11:03:06 2021 +0000

    libstdc++: Move std::to_address tests to more appropriate place
    
    Some of the checks in 20_util/pointer_traits/lwg3545.cc really belong in
    20_util/to_address/lwg3545 instead.
    
    This also fixes the ordering of the dg-options and dg-do directives.
    
    libstdc++-v3/ChangeLog:
    
            * testsuite/20_util/pointer_traits/lwg3545.cc: Move to_address
            tests to ...
            * testsuite/20_util/to_address/lwg3545.cc: ... here. Add -std
            option before checking effective target.

Diff:
---
 .../testsuite/20_util/pointer_traits/lwg3545.cc    | 19 ---------------
 .../testsuite/20_util/to_address/lwg3545.cc        | 27 +++++++++++++++++++++-
 2 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/libstdc++-v3/testsuite/20_util/pointer_traits/lwg3545.cc b/libstdc++-v3/testsuite/20_util/pointer_traits/lwg3545.cc
index 8325cb66d08..08c3ed01b75 100644
--- a/libstdc++-v3/testsuite/20_util/pointer_traits/lwg3545.cc
+++ b/libstdc++-v3/testsuite/20_util/pointer_traits/lwg3545.cc
@@ -99,22 +99,3 @@ static_assert( is_same<pointer<Ctraits>, clever_ptr<char>>::value, "" );
 static_assert( is_same<difference_type<Ctraits>, std::ptrdiff_t>::value, "" );
 static_assert( is_same<rebind<Ctraits>, clever_ptr<short>>::value, "" );
 static_assert( is_same<pointer_to<Ctraits>, clever_ptr<char>>::value, "" );
-
-#if __cplusplus >= 202002L
-static_assert( std::to_address(clever_ptr<char>{}) == &clever_ptr<char>::obj, "" );
-
-int the_int;
-
-template<>
-struct std::pointer_traits<clever_ptr<int>>
-{
-  using element_type = int;
-  using difference_type = std::ptrdiff_t;
-  using pointer = clever_ptr<int>;
-
-  static constexpr int* to_address(pointer p) { return &the_int; }
-};
-
-// Should use pointer_traits<clever_ptr<int>>::to_address
-static_assert( std::to_address(clever_ptr<int>{}) == &the_int, "" );
-#endif
diff --git a/libstdc++-v3/testsuite/20_util/to_address/lwg3545.cc b/libstdc++-v3/testsuite/20_util/to_address/lwg3545.cc
index 4dc5fdcdde0..a80ac29b2c9 100644
--- a/libstdc++-v3/testsuite/20_util/to_address/lwg3545.cc
+++ b/libstdc++-v3/testsuite/20_util/to_address/lwg3545.cc
@@ -1,5 +1,5 @@
-// { dg-do compile { target c++20 } }
 // { dg-options "-std=gnu++20" }
+// { dg-do compile { target c++20 } }
 
 #include <memory>
 
@@ -10,3 +10,28 @@ template<typename T, bool> struct nttp_ptr
 
 // This gives an error in C++20, which the LWG 3545 resolution should fix:
 auto x = std::to_address( nttp_ptr<int, true>() );
+
+template<typename T>
+struct clever_ptr
+{
+  static T obj;
+  constexpr T* operator->() const { return &obj; }
+};
+
+// pointer_traits specialization is valid, but to_address uses operator->
+static_assert( std::to_address(clever_ptr<char>{}) == &clever_ptr<char>::obj );
+
+int the_int;
+
+template<>
+struct std::pointer_traits<clever_ptr<int>>
+{
+  using element_type = int;
+  using difference_type = std::ptrdiff_t;
+  using pointer = clever_ptr<int>;
+
+  static constexpr int* to_address(pointer p) { return &the_int; }
+};
+
+// Uses pointer_traits<clever_ptr<int>>::to_address
+static_assert( std::to_address(clever_ptr<int>{}) == &the_int );