[libc++] Implement P0980R1 (constexpr std::string)

Reviewed By: #libc, ldionne

Spies: daltenty, sdasgup3, ldionne, arichardson, MTC, ChuanqiXu, mehdi_amini, shauheen, antiagainst, nicolasvasilache, arpith-jacob, mgester, lucyrfox, aartbik, liufengdb, stephenneuendorffer, Joonsoo, grosul1, Kayjukh, jurahul, msifontes, tatianashp, rdzhabarov, teijeong, cota, dcaballe, Chia-hungDuan, wrengr, wenzhicui, arphaman, Mordante, miscco, Quuxplusone, smeenai, libcxx-commits

Differential Revision: https://reviews.llvm.org/D110598

1 files changed, 6 insertions, 4 deletions

diff --git a/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/string_view.pass.cpp b/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/string_view.pass.cpp
index 3b8e63b9a7fc..c378d40d5481 100644
--- a/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/string_view.pass.cpp
+++ b/libcxx/test/std/strings/basic.string/string.modifiers/string_insert/string_view.pass.cpp
@@ -6,10 +6,12 @@
 //
 //===----------------------------------------------------------------------===//
 
+// XFAIL: LIBCXX-AIX-FIXME
+
 // <string>
 
 // basic_string<charT,traits,Allocator>&
-//   insert(size_type pos, string_view sv);
+//   insert(size_type pos, string_view sv); // constexpr since C++20
 
 #include <string>
 #include <stdexcept>
@@ -31,7 +33,7 @@ test(S s, typename S::size_type pos, SV sv, S expected)
         assert(s == expected);
     }
 #ifndef TEST_HAS_NO_EXCEPTIONS
-    else
+    else if (!TEST_IS_CONSTANT_EVALUATED)
     {
         try
         {
@@ -47,7 +49,7 @@ test(S s, typename S::size_type pos, SV sv, S expected)
 #endif
 }
 
-bool test() {
+TEST_CONSTEXPR_CXX20 bool test() {
   {
     typedef std::string S;
     typedef std::string_view SV;
@@ -242,7 +244,7 @@ int main(int, char**)
 {
   test();
 #if TEST_STD_VER > 17
-  // static_assert(test());
+  static_assert(test());
 #endif
 
   return 0;