From a897e98da47e8ffc99f985d498c8050d9af8cfee Mon Sep 17 00:00:00 2001
From: Felipe Pena <felipensp@gmail.com>
Date: Sat, 16 Aug 2025 09:52:30 -0300
Subject: [PATCH] fix

---
 vlib/v/checker/fn.v                                 |  3 +++
 .../tests/empty_arr_to_generic_param_err.out        | 13 +++++++++++++
 .../checker/tests/empty_arr_to_generic_param_err.vv | 10 ++++++++++
 3 files changed, 26 insertions(+)
 create mode 100644 vlib/v/checker/tests/empty_arr_to_generic_param_err.out
 create mode 100644 vlib/v/checker/tests/empty_arr_to_generic_param_err.vv

diff --git a/vlib/v/checker/fn.v b/vlib/v/checker/fn.v
index bbd1046c13..3ce1d5db0c 100644
--- a/vlib/v/checker/fn.v
+++ b/vlib/v/checker/fn.v
@@ -2576,6 +2576,9 @@ fn (mut c Checker) method_call(mut node ast.CallExpr, mut continue_check &bool)
 			}
 		}
 		if exp_arg_typ.has_flag(.generic) {
+			if arg.expr is ast.ArrayInit && arg.expr.exprs.len == 0 {
+				c.error('cannot use empty array as generic argument', arg.pos)
+			}
 			method_concrete_types := if method_generic_names_len == rec_concrete_types.len {
 				rec_concrete_types
 			} else {
diff --git a/vlib/v/checker/tests/empty_arr_to_generic_param_err.out b/vlib/v/checker/tests/empty_arr_to_generic_param_err.out
new file mode 100644
index 0000000000..95471d0934
--- /dev/null
+++ b/vlib/v/checker/tests/empty_arr_to_generic_param_err.out
@@ -0,0 +1,13 @@
+vlib/v/checker/tests/empty_arr_to_generic_param_err.vv:8:4: error: cannot use empty array as generic argument
+    6 | 
+    7 | fn main() {
+    8 |     t([])
+      |       ~~
+    9 |     Foo{}.t([])
+   10 | }
+vlib/v/checker/tests/empty_arr_to_generic_param_err.vv:9:10: error: cannot use empty array as generic argument
+    7 | fn main() {
+    8 |     t([])
+    9 |     Foo{}.t([])
+      |             ~~
+   10 | }
diff --git a/vlib/v/checker/tests/empty_arr_to_generic_param_err.vv b/vlib/v/checker/tests/empty_arr_to_generic_param_err.vv
new file mode 100644
index 0000000000..ad91667872
--- /dev/null
+++ b/vlib/v/checker/tests/empty_arr_to_generic_param_err.vv
@@ -0,0 +1,10 @@
+fn t[T](a []T) {}
+
+struct Foo {}
+
+fn (t &Foo) t[T](a []T) {}
+
+fn main() {
+	t([])
+	Foo{}.t([])
+}