[libcxx-commits] [libcxx] [libc++] Add the allocator parameter in basic_string::substr (PR #110207)

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llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-libcxx

Author: Alexandre Arsenault (alxarsenault)

<details>
<summary>Changes</summary>

When using a non-default constructible allocator in `std::basic_string`, the `substr` method should pass it's allocator to construct the substring.

---
Full diff: https://github.com/llvm/llvm-project/pull/110207.diff


1 Files Affected:

- (modified) libcxx/include/string (+3-3) 


``````````diff
diff --git a/libcxx/include/string b/libcxx/include/string
index fdb189016bfbac..b49b61567cdc2b 100644
--- a/libcxx/include/string
+++ b/libcxx/include/string
@@ -1683,15 +1683,15 @@ public:
 #if _LIBCPP_STD_VER <= 20
   _LIBCPP_HIDE_FROM_ABI _LIBCPP_CONSTEXPR_SINCE_CXX20 basic_string
   substr(size_type __pos = 0, size_type __n = npos) const {
-    return basic_string(*this, __pos, __n);
+    return basic_string(*this, __pos, __n, __alloc());
   }
 #else
   _LIBCPP_HIDE_FROM_ABI constexpr basic_string substr(size_type __pos = 0, size_type __n = npos) const& {
-    return basic_string(*this, __pos, __n);
+    return basic_string(*this, __pos, __n, __alloc());
   }
 
   _LIBCPP_HIDE_FROM_ABI constexpr basic_string substr(size_type __pos = 0, size_type __n = npos) && {
-    return basic_string(std::move(*this), __pos, __n);
+    return basic_string(std::move(*this), __pos, __n, __alloc());
   }
 #endif
 

``````````

</details>


https://github.com/llvm/llvm-project/pull/110207