[libcxx-commits] [libcxx] [libc++] Refactor memory allocation in basic_string (PR #128423)

[Louis Dionne via libcxx-commits]

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@@ -2250,6 +2230,63 @@ private:
     return __is_long() ? __get_long_pointer() : __get_short_pointer();
   }
 
+  // Internal buffer management
+  // --------------------------
+  //
+  // These functions are only responsible for managing the buffer itself, not the value inside the buffer. As such,
+  // none of these facilities ensure that there is a null terminator at `data()[size()]`.
+
+  // Allocate a buffer of __capacity size with __alloc and return it
+  _LIBCPP_HIDE_FROM_ABI static _LIBCPP_CONSTEXPR_SINCE_CXX20 __alloc_result
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ldionne wrote:

Should we return a `__long` from here instead? This might also remove the need to touch `__allocate_at_least`?

And then should `struct __rep` have a constructor from `__long` and from `__short` directly?

https://github.com/llvm/llvm-project/pull/128423