[libcxx-commits] [libcxx] [libc++] Optimize basic_string::operator= (PR #224535)

[Louis Dionne via libcxx-commits]

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@@ -2727,28 +2727,40 @@ basic_string<_CharT, _Traits, _Allocator>::__grow_by_without_replace(
 
 template <class _CharT, class _Traits, class _Allocator>
 template <bool __is_short>
-_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE basic_string<_CharT, _Traits, _Allocator>&
+_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_NOINLINE void
 basic_string<_CharT, _Traits, _Allocator>::__assign_no_alias(const value_type* __s, size_type __n) {
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ldionne wrote:

Suggestion: pass a `string const&` instead to make it clear that `__s` and `__n` are just the string's data and the size of the string.

Otherwise, we could rename `size_type __n` to `size_type __size` and document that `__size == strlen(__s)` -- basically this is just a way for the caller to pass already known information down.

https://github.com/llvm/llvm-project/pull/224535