From 883052a6bbd49d15401d1d5f4a2559f4bd9327e3 Mon Sep 17 00:00:00 2001
From: Christoffer Lerno <christoffer@aegik.com>
Date: Wed, 22 Oct 2025 23:48:32 +0200
Subject: [PATCH] Improved generic inference in initializers #2541.

---
 releasenotes.md                              |  1 +
 src/compiler/sema_expr.c                     | 18 +++++++++++++++---
 test/test_suite/generic/generic_inference.c3 | 13 +++++++++++++
 3 files changed, 29 insertions(+), 3 deletions(-)
 create mode 100644 test/test_suite/generic/generic_inference.c3

diff --git a/releasenotes.md b/releasenotes.md
index 489b6ca0a..6b1059d13 100644
--- a/releasenotes.md
+++ b/releasenotes.md
@@ -10,6 +10,7 @@
 - Allow `..` ranges to use "a..a-1" in order to express zero length.
 - Disallow aliasing of `@local` symbols with a higher visibility in the alias.
 - Add `--max-macro-iterations` to set macro iteration limit.
+- Improved generic inference in initializers #2541. 
 
 ### Fixes
 - Bug in `io::write_using_write_byte`.
diff --git a/src/compiler/sema_expr.c b/src/compiler/sema_expr.c
index ba3b12604..868f950dc 100644
--- a/src/compiler/sema_expr.c
+++ b/src/compiler/sema_expr.c
@@ -7427,12 +7427,12 @@ static bool sema_binary_arithmetic_promotion(SemaContext *context, Expr *left, E
 		right_type = type_no_optional(right->type)->canonical;
 		if (type_is_pointer_like(left_type))
 		{
-			*operator_overload_ref = OVERLOAD_NONE;
+			*operator_overload_ref = OVERLOAD_NONE; // NOLINT
 			return sema_expr_analyse_ptr_add(context, parent, left, right, left_type, right_type, cast_to_iptr, failed_ref);
 		}
 		if (type_is_pointer_like(right_type))
 		{
-			*operator_overload_ref = OVERLOAD_NONE;
+			*operator_overload_ref = OVERLOAD_NONE; // NOLINT
 			return sema_expr_analyse_ptr_add(context, parent, right, left, right_type, left_type, cast_to_iptr, failed_ref);
 		}
 	}
@@ -11597,7 +11597,19 @@ bool sema_analyse_expr_rhs(SemaContext *context, Type *to, Expr *expr, bool allo
 	}
 	else
 	{
-		if (!sema_analyse_inferred_expr(context, to, expr, no_match_ref)) return false;
+		Module *generic;
+		if (to && (generic = type_find_generic(to)) != NULL)
+		{
+			Module *generic_module = context->generic.infer;
+			context->generic.infer = generic;
+			bool success = sema_analyse_inferred_expr(context, to, expr, no_match_ref);
+			context->generic.infer = generic_module;
+			if (!success) return false;
+		}
+		else
+		{
+			if (!sema_analyse_inferred_expr(context, to, expr, no_match_ref)) return false;
+		}
 	}
 	if (!sema_cast_rvalue(context, expr, true)) return false;
 	if (to) to = type_no_optional(to);
diff --git a/test/test_suite/generic/generic_inference.c3 b/test/test_suite/generic/generic_inference.c3
new file mode 100644
index 000000000..bb9489cc8
--- /dev/null
+++ b/test/test_suite/generic/generic_inference.c3
@@ -0,0 +1,13 @@
+import std::collections::linkedlist;
+struct Foo
+{
+	LinkedList {int} x;
+}
+
+fn int main(String[] args)
+{
+	Foo f;
+	f.x = linkedlist::@new(tmem);
+	Foo f1 = { .x = linkedlist::@new(tmem) };
+	return 0;
+}
\ No newline at end of file