[libcxx-commits] [libcxx] [libc++][NFC] Simplify string a bit (PR #127135)

[Peng Liu via libcxx-commits]

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@@ -3014,10 +3004,11 @@ template <class _CharT, class _Traits, class _Allocator>
 _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string<_CharT, _Traits, _Allocator>&
 basic_string<_CharT, _Traits, _Allocator>::assign(const value_type* __s) {
   _LIBCPP_ASSERT_NON_NULL(__s != nullptr, "string::assign received nullptr");
-  return __builtin_constant_p(*__s)
-           ? (__fits_in_sso(traits_type::length(__s)) ? __assign_short(__s, traits_type::length(__s))
-                                                      : __assign_external(__s, traits_type::length(__s)))
-           : __assign_external(__s);
+  if (__builtin_constant_p(*__s)) {
+    const size_type __n = traits_type::length(__s);
+    return __fits_in_sso(__n) ? __assign_short(__s, __n) : __assign_external(__s, __n);
+  }
+  return __assign_external(__s);
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winner245 wrote:

Looks great—adopted! I have also double-checked that even with basic compiler optimization level (-O1), they yield the same code (https://godbolt.org/z/3jqM8cYEv), and the way you suggested is definitely the simplest. 


https://github.com/llvm/llvm-project/pull/127135