From db9b35a0c2fd3840ef9f9ac297d70e7e748a1812 Mon Sep 17 00:00:00 2001
From: Tim Rid <6593626+timrid@users.noreply.github.com>
Date: Sun, 13 Feb 2022 16:04:27 +0100
Subject: [PATCH] added `Constructable` Protocol

---
 construct_typed/generic_wrapper.py | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/construct_typed/generic_wrapper.py b/construct_typed/generic_wrapper.py
index aa4af4c..75c0ac2 100644
--- a/construct_typed/generic_wrapper.py
+++ b/construct_typed/generic_wrapper.py
@@ -39,3 +39,20 @@ else:
 
     ConstantOrContextLambda = t.Union[ValueType, t.Callable[[Context], t.Any]]
     PathType = str
+
+
+@t.runtime_checkable
+class Constructable(t.Protocol[ParsedType, BuildTypes]):
+    def __construct__(self) -> "Construct[ParsedType, BuildTypes]":
+        raise NotImplementedError
+
+
+def construct(
+    constr: t.Union[
+        Constructable[ParsedType, BuildTypes], "Construct[ParsedType, BuildTypes]"
+    ],
+) -> Construct[ParsedType, BuildTypes]:
+    """Get construct instance of `Constructable` or `Construct`"""
+    if isinstance(constr, Constructable):
+        constr = constr.__construct__()
+    return constr