From d451794386e0cc2e3e61e979310e60e4d2278bac Mon Sep 17 00:00:00 2001
From: donbarbos <donbarbos@proton.me>
Date: Sat, 10 Jan 2026 22:44:01 +0400
Subject: [PATCH 1/3] [sre_compile] Use TypeGuard for isstring

Source: https://github.com/python/cpython/blob/aa8578dc54df2af9daa3353566359e602e5905cf/Lib/re/_compiler.py#L587
---
 stdlib/sre_compile.pyi | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/stdlib/sre_compile.pyi b/stdlib/sre_compile.pyi
index d8f0b7937e99..9dd54c7a91a6 100644
--- a/stdlib/sre_compile.pyi
+++ b/stdlib/sre_compile.pyi
@@ -3,9 +3,10 @@ from sre_constants import *
 from sre_constants import _NamedIntConstant
 from sre_parse import SubPattern
 from typing import Any, Final
+from typing_extensions import TypeGuard
 
 MAXCODE: Final[int]
 
 def dis(code: list[_NamedIntConstant]) -> None: ...
-def isstring(obj: Any) -> bool: ...
+def isstring(obj: object) -> TypeGuard[str | bytes]: ...
 def compile(p: str | bytes | SubPattern, flags: int = 0) -> Pattern[Any]: ...

From da5179cbd94767211d06d42e51d8f35ed43c05f5 Mon Sep 17 00:00:00 2001
From: donbarbos <donbarbos@proton.me>
Date: Sun, 11 Jan 2026 01:56:06 +0400
Subject: [PATCH 2/3] Retain knowledge about str,bytes types

---
 stdlib/sre_compile.pyi | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/stdlib/sre_compile.pyi b/stdlib/sre_compile.pyi
index 9dd54c7a91a6..4c0a11a3cc76 100644
--- a/stdlib/sre_compile.pyi
+++ b/stdlib/sre_compile.pyi
@@ -2,11 +2,16 @@ from re import Pattern
 from sre_constants import *
 from sre_constants import _NamedIntConstant
 from sre_parse import SubPattern
-from typing import Any, Final
+from typing import Any, Final, Literal, overload
 from typing_extensions import TypeGuard
 
 MAXCODE: Final[int]
 
 def dis(code: list[_NamedIntConstant]) -> None: ...
+@overload
+def isstring(obj: str) -> Literal[True]: ...
+@overload
+def isstring(obj: bytes) -> Literal[True]: ...
+@overload
 def isstring(obj: object) -> TypeGuard[str | bytes]: ...
 def compile(p: str | bytes | SubPattern, flags: int = 0) -> Pattern[Any]: ...

From 51071a53bdd54e3ef4914be7f426b8c6ab49274b Mon Sep 17 00:00:00 2001
From: Semyon Moroz <donbarbos@proton.me>
Date: Sat, 10 Jan 2026 22:03:21 +0000
Subject: [PATCH 3/3] merge into one overload

---
 stdlib/sre_compile.pyi | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/stdlib/sre_compile.pyi b/stdlib/sre_compile.pyi
index 4c0a11a3cc76..e29d63d48591 100644
--- a/stdlib/sre_compile.pyi
+++ b/stdlib/sre_compile.pyi
@@ -9,9 +9,7 @@ MAXCODE: Final[int]
 
 def dis(code: list[_NamedIntConstant]) -> None: ...
 @overload
-def isstring(obj: str) -> Literal[True]: ...
-@overload
-def isstring(obj: bytes) -> Literal[True]: ...
+def isstring(obj: str | bytes) -> Literal[True]: ...
 @overload
 def isstring(obj: object) -> TypeGuard[str | bytes]: ...
 def compile(p: str | bytes | SubPattern, flags: int = 0) -> Pattern[Any]: ...