Explicitly make T_Retval covariant

agronholm · Jun 30, 2023 · 43e3e26 · 43e3e26
1 parent f7d3f5f
commit 43e3e26
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Showing 11 changed files with 11 additions and 11 deletions.
diff --git a/src/anyio/_backends/_asyncio.py b/src/anyio/_backends/_asyncio.py
@@ -276,7 +276,7 @@ def _do_shutdown(future: asyncio.futures.Future) -> None:
             thread.join()
 
 
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 T_contra = TypeVar("T_contra", contravariant=True)
 PosArgsT = TypeVarTuple("PosArgsT")
 P = ParamSpec("P")

diff --git a/src/anyio/_backends/_trio.py b/src/anyio/_backends/_trio.py
@@ -69,7 +69,7 @@
     from typing_extensions import TypeVarTuple, Unpack
 
 T = TypeVar("T")
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 T_SockAddr = TypeVar("T_SockAddr", str, IPSockAddrType)
 PosArgsT = TypeVarTuple("PosArgsT")
 

diff --git a/src/anyio/_core/_eventloop.py b/src/anyio/_core/_eventloop.py
@@ -21,7 +21,7 @@
 # This must be updated when new backends are introduced
 BACKENDS = "asyncio", "trio"
 
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 PosArgsT = TypeVarTuple("PosArgsT")
 
 threadlocals = threading.local()

diff --git a/src/anyio/abc/_eventloop.py b/src/anyio/abc/_eventloop.py
@@ -38,7 +38,7 @@
     from ._tasks import TaskGroup
     from ._testing import TestRunner
 
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 
 
 class AsyncBackend(metaclass=ABCMeta):

diff --git a/src/anyio/abc/_sockets.py b/src/anyio/abc/_sockets.py
@@ -23,7 +23,7 @@
 SockAddrType = Union[IPSockAddrType, str]
 UDPPacketType = Tuple[bytes, IPSockAddrType]
 UNIXDatagramPacketType = Tuple[bytes, str]
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 
 
 class _NullAsyncContextManager:

diff --git a/src/anyio/abc/_tasks.py b/src/anyio/abc/_tasks.py
@@ -14,7 +14,7 @@
 if TYPE_CHECKING:
     from .._core._tasks import CancelScope
 
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 T_contra = TypeVar("T_contra", contravariant=True)
 PosArgsT = TypeVarTuple("PosArgsT")
 

diff --git a/src/anyio/from_thread.py b/src/anyio/from_thread.py
@@ -30,7 +30,7 @@
 else:
     from typing_extensions import TypeVarTuple, Unpack
 
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 T_co = TypeVar("T_co", covariant=True)
 PosArgsT = TypeVarTuple("PosArgsT")
 

diff --git a/src/anyio/streams/tls.py b/src/anyio/streams/tls.py
@@ -17,7 +17,7 @@
 from .._core._typedattr import TypedAttributeSet, typed_attribute
 from ..abc import AnyByteStream, ByteStream, Listener, TaskGroup
 
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 _PCTRTT = Tuple[Tuple[str, str], ...]
 _PCTRTTT = Tuple[_PCTRTT, ...]
 

diff --git a/src/anyio/to_process.py b/src/anyio/to_process.py
@@ -25,7 +25,7 @@
 
 WORKER_MAX_IDLE_TIME = 300  # 5 minutes
 
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 PosArgsT = TypeVarTuple("PosArgsT")
 
 _process_pool_workers: RunVar[set[Process]] = RunVar("_process_pool_workers")

diff --git a/src/anyio/to_thread.py b/src/anyio/to_thread.py
@@ -13,7 +13,7 @@
 else:
     from typing_extensions import TypeVarTuple, Unpack
 
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 PosArgsT = TypeVarTuple("PosArgsT")
 
 

diff --git a/tests/test_from_thread.py b/tests/test_from_thread.py
@@ -38,7 +38,7 @@
 
 pytestmark = pytest.mark.anyio
 
-T_Retval = TypeVar("T_Retval")
+T_Retval = TypeVar("T_Retval", covariant=True)
 
 
 async def async_add(a: int, b: int) -> int: