simplify pydantic type conversion using pydantic.TypeAdapter

typer/main.py

@@ -12,7 +12,7 @@
 from uuid import UUID
 
 import click
-from typing_extensions import Annotated, TypeAlias, get_args, get_origin
+from typing_extensions import Annotated, get_args, get_origin
 
 from ._typing import is_union
 from .completion import get_completion_inspect_parameters
@@ -68,15 +68,11 @@ def is_pydantic_type(type_: Any) -> bool:
 
     def pydantic_convertor(type_: type) -> Callable[[str], Any]:
         """Create a convertor for a parameter annotated with a pydantic type."""
-        T: TypeAlias = type_  # type: ignore[valid-type]
+        adapter = pydantic.TypeAdapter(type_)
 
-        @pydantic.validate_call
-        def internal_convertor(value: T) -> T:
-            return value
-
-        def convertor(value: str) -> T:
+        def convertor(value: str):
             try:
-                return internal_convertor(value)
+                return adapter.validate_python(value)
             except pydantic.ValidationError as e:
                 error_message = e.errors(
                     include_context=False, include_input=False, include_url=False