Drop some newly obsolete __cplusplus version checks

...after 1eef07805021b7ca26a1a8894809b6d995747ba1 "Bump baseline to C++20".

Which revealed that at least for VS 2019 16.11.30 (but not for at least VS 2022
17.7.4), in /clr mode (e.g., when compiling
cli_ure/source/climaker/climaker_app.cxx), the -std:c++20 is effectively
ignored, and compilation of such source files failed with

> include\rtl/string.hxx(191): error C2955: 'rtl::OStringLiteral': use of class template requires template argument list
> include\rtl/string.hxx(88): note: see declaration of 'rtl::OStringLiteral'
> include\rtl/string.hxx(191): error C7592: a non-type template-parameter of type 'rtl::OStringLiteral' requires at least '/std:c++20'
> include\rtl/string.hxx(397): error C2955: 'rtl::OStringLiteral': use of class template requires template argument list
> include\rtl/string.hxx(88): note: see declaration of 'rtl::OStringLiteral'

etc.  To work around that, keep the 27d1f3ac016d77d3c907cebedca558308f366855
"O[U]String literals (unusable for now, C++20 only)" functionality disabled when
compiling /clr sources (i.e., where _MANAGED is defined) for that old compiler.

Change-Id: If62ceef5f8e55a828b880f197111fe387e4953fe
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/157205
Tested-by: Jenkins
Reviewed-by: Stephan Bergmann <sbergman@redhat.com>

3 files changed, 10 insertions, 10 deletions

diff --git a/include/rtl/string.hxx b/include/rtl/string.hxx
index eb7f137a203c..72b046e26a0b 100644
--- a/include/rtl/string.hxx
+++ b/include/rtl/string.hxx
@@ -186,7 +186,7 @@ private:
     rtl_String* pData;
 };
 
-#if __cplusplus >= 202002L
+#if !(defined _MSC_VER && _MSC_VER <= 1929 && defined _MANAGED)
 
 namespace detail {
 
@@ -396,7 +396,7 @@ public:
     /// @endcond
 #endif
 
-#if defined LIBO_INTERNAL_ONLY && __cplusplus >= 202002L
+#if defined LIBO_INTERNAL_ONLY && !(defined _MSC_VER && _MSC_VER <= 1929 && defined _MANAGED)
     // For operator ""_tstr:
     template<OStringLiteral L> constexpr OString(detail::OStringHolder<L> const & holder):
         pData(const_cast<rtl_String *>(&holder.literal.str)) {}
@@ -472,12 +472,12 @@ public:
     /**
       Release the string data.
     */
-#if defined LIBO_INTERNAL_ONLY && __cplusplus >= 202002L
+#if defined LIBO_INTERNAL_ONLY && !(defined _MSC_VER && _MSC_VER <= 1929 && defined _MANAGED)
     constexpr
 #endif
     ~OString()
     {
-#if defined LIBO_INTERNAL_ONLY && __cplusplus >= 202002L
+#if defined LIBO_INTERNAL_ONLY && !(defined _MSC_VER && _MSC_VER <= 1929 && defined _MANAGED)
         if (std::is_constant_evaluated()) {
            //TODO: We would want to
            //
@@ -2393,7 +2393,7 @@ using ::rtl::OStringHash;
 using ::rtl::OStringLiteral;
 #endif
 
-#if defined LIBO_INTERNAL_ONLY && __cplusplus >= 202002L
+#if defined LIBO_INTERNAL_ONLY && !(defined _MSC_VER && _MSC_VER <= 1929 && defined _MANAGED)
 
 template<
 #if defined RTL_STRING_UNITTEST
diff --git a/include/rtl/ustring.hxx b/include/rtl/ustring.hxx
index 34d4fd8f5be5..764ad026bdff 100644
--- a/include/rtl/ustring.hxx
+++ b/include/rtl/ustring.hxx
@@ -440,7 +440,7 @@ public:
     /// @endcond
 #endif
 
-#if defined LIBO_INTERNAL_ONLY && __cplusplus >= 202002L
+#if defined LIBO_INTERNAL_ONLY && !(defined _MSC_VER && _MSC_VER <= 1929 && defined _MANAGED)
     // For operator ""_tstr:
     template<OStringLiteral L> OUString(detail::OStringHolder<L> const & holder) {
         pData = nullptr;
@@ -545,12 +545,12 @@ public:
     /**
       Release the string data.
     */
-#if defined LIBO_INTERNAL_ONLY && __cplusplus >= 202002L
+#if defined LIBO_INTERNAL_ONLY && !(defined _MSC_VER && _MSC_VER <= 1929 && defined _MANAGED)
     constexpr
 #endif
     ~OUString()
     {
-#if defined LIBO_INTERNAL_ONLY && __cplusplus >= 202002L
+#if defined LIBO_INTERNAL_ONLY && !(defined _MSC_VER && _MSC_VER <= 1929 && defined _MANAGED)
         if (std::is_constant_evaluated()) {
            //TODO: We would want to
            //
@@ -3590,7 +3590,7 @@ using ::rtl::OUStringChar;
 using ::rtl::Concat2View;
 #endif
 
-#if defined LIBO_INTERNAL_ONLY && __cplusplus >= 202002L
+#if defined LIBO_INTERNAL_ONLY && !(defined _MSC_VER && _MSC_VER <= 1929 && defined _MANAGED)
 
 template<
 #if defined RTL_STRING_UNITTEST
diff --git a/include/unotools/weakref.hxx b/include/unotools/weakref.hxx
index 14ee6d424f62..0cab7d0e9b2a 100644
--- a/include/unotools/weakref.hxx
+++ b/include/unotools/weakref.hxx
@@ -115,7 +115,7 @@ public:
          @return hard reference or null, if the weakly referenced interface has gone
     */
     rtl::Reference<interface_type> SAL_CALL get() const
-#if __cplusplus >= 202002L && !(defined __clang__ && __clang_major__ <= 15)
+#if !(defined __clang__ && __clang_major__ <= 15)
         requires(!cppu::detail::isUnoInterfaceType<interface_type>)
 #endif
     {