From d2f4d08485367db51e5e0a25af5bc67806bf736e Mon Sep 17 00:00:00 2001
From: tserg <8017125+tserg@users.noreply.github.com>
Date: Mon, 8 May 2023 22:28:54 +0800
Subject: [PATCH] use _BytestringT

---
 vyper/builtins/_convert.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/vyper/builtins/_convert.py b/vyper/builtins/_convert.py
index 3fc12c6c20..546207072a 100644
--- a/vyper/builtins/_convert.py
+++ b/vyper/builtins/_convert.py
@@ -267,7 +267,7 @@ def _literal_decimal(expr, arg_typ, out_typ):
 def to_bool(expr, arg, out_typ):
     _check_bytes(expr, arg, out_typ, 32)  # should we restrict to Bytes[1]?
 
-    if isinstance(arg.typ, (BytesT, StringT)):
+    if isinstance(arg.typ, _BytestringT):
         # no clamp. checks for any nonzero bytes.
         arg = _bytes_to_num(arg, out_typ, signed=False)