[libcxx-commits] [libcxx] [libcxx] Allow string to use SSO in constant evaluation. (PR #66576)

[James Y Knight via libcxx-commits]

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@@ -1729,8 +1729,10 @@ private:
 
     _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20
     bool __is_long() const _NOEXCEPT {
-        if (__libcpp_is_constant_evaluated())
-            return true;
+        if (__libcpp_is_constant_evaluated()) {
+            if (__builtin_constant_p(__r_.first().__l.__is_long_))
+                return __r_.first().__l.__is_long_;
+        }
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jyknight wrote:

Done.

https://github.com/llvm/llvm-project/pull/66576