[libc++] Prepare string.modifiers tests for constexpr

Reviewed By: ldionne, #libc

Spies: libcxx-commits

Differential Revision: https://reviews.llvm.org/D119329

1 files changed, 18 insertions, 9 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 129389a9a7b0..3b8e63b9a7fc 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
@@ -19,7 +19,7 @@
 #include "min_allocator.h"
 
 template <class S, class SV>
-void
+TEST_CONSTEXPR_CXX20 void
 test(S s, typename S::size_type pos, SV sv, S expected)
 {
     const typename S::size_type old_size = s.size();
@@ -47,9 +47,8 @@ test(S s, typename S::size_type pos, SV sv, S expected)
 #endif
 }
 
-int main(int, char**)
-{
-    {
+bool test() {
+  {
     typedef std::string S;
     typedef std::string_view SV;
     test(S(""), 0, SV(""), S(""));
@@ -132,9 +131,9 @@ int main(int, char**)
     test(S("abcdefghijklmnopqrst"), 21, SV("12345"), S("can't happen"));
     test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), S("can't happen"));
     test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), S("can't happen"));
-    }
+  }
 #if TEST_STD_VER >= 11
-    {
+  {
     typedef std::basic_string<char, std::char_traits<char>, min_allocator<char>> S;
     typedef std::string_view SV;
     test(S(""), 0, SV(""), S(""));
@@ -217,10 +216,10 @@ int main(int, char**)
     test(S("abcdefghijklmnopqrst"), 21, SV("12345"), S("can't happen"));
     test(S("abcdefghijklmnopqrst"), 21, SV("1234567890"), S("can't happen"));
     test(S("abcdefghijklmnopqrst"), 21, SV("12345678901234567890"), S("can't happen"));
-    }
+  }
 #endif
 
-    { // test inserting into self
+  { // test inserting into self
     typedef std::string S;
     S s_short = "123/";
     S s_long  = "Lorem ipsum dolor sit amet, consectetur/";
@@ -234,7 +233,17 @@ int main(int, char**)
 
     s_long.insert(0, s_long.c_str());
     assert(s_long == "Lorem ipsum dolor sit amet, consectetur/Lorem ipsum dolor sit amet, consectetur/");
-    }
+  }
+
+  return true;
+}
+
+int main(int, char**)
+{
+  test();
+#if TEST_STD_VER > 17
+  // static_assert(test());
+#endif
 
   return 0;
 }