From 3e628d09d9bbd425c24b482297a574534c45005d Mon Sep 17 00:00:00 2001
From: JMD <56417208+StunxFS@users.noreply.github.com>
Date: Fri, 24 Oct 2025 15:34:22 -0400
Subject: [PATCH] checker: fix cast from an empty struct to option (fix #25566)
 (#25581)

---
 vlib/v/checker/checker.v                         | 3 ++-
 vlib/v/tests/casts/cast_empty_struct_to_option.v | 7 +++++++
 2 files changed, 9 insertions(+), 1 deletion(-)
 create mode 100644 vlib/v/tests/casts/cast_empty_struct_to_option.v

diff --git a/vlib/v/checker/checker.v b/vlib/v/checker/checker.v
index 7fb181e62..1ec10f1e9 100644
--- a/vlib/v/checker/checker.v
+++ b/vlib/v/checker/checker.v
@@ -3550,7 +3550,8 @@ fn (mut c Checker) cast_expr(mut node ast.CastExpr) ast.Type {
 				c.warn('casting to struct is deprecated, use e.g. `Struct{...expr}` instead',
 					node.pos)
 			}
-			if !c.check_struct_signature(from_sym.info, to_sym.info) {
+			if from_type.idx() != to_type.idx()
+				&& !c.check_struct_signature(from_sym.info, to_sym.info) {
 				c.error('cannot convert struct `${from_sym.name}` to struct `${to_sym.name}`',
 					node.pos)
 			}
diff --git a/vlib/v/tests/casts/cast_empty_struct_to_option.v b/vlib/v/tests/casts/cast_empty_struct_to_option.v
new file mode 100644
index 000000000..39a7e966e
--- /dev/null
+++ b/vlib/v/tests/casts/cast_empty_struct_to_option.v
@@ -0,0 +1,7 @@
+struct Struct {}
+
+fn main() {
+	s := ?Struct(Struct{})
+	a := s or { panic('none') }
+	assert a == Struct{}
+}
-- 
2.39.5