fixes

examples/issue-0018.sx

@@ -0,0 +1,89 @@
+// issue-0018: Dot-shorthand `.{...}` for struct with protocol field causes
+// LLVM verification error when used in List(T).append from 2+ different
+// struct methods.
+//
+// Trigger: TWO or more structs each with `List(Container)` calling
+//          `.append(.{ child = d })` — using dot-shorthand.
+//
+// Works: Only 1 struct doing it, or using explicit `Container.{ child = d }`.
+// Fails: 2+ structs → `Invalid InsertValueInst operands!`
+//        `%si = insertvalue i64 undef, { ptr, ptr } %load, 0`
+//
+// Likely a monomorphization issue in `List(T).append` when the dot-shorthand
+// type inference is resolved from multiple call sites.
+
+#import "modules/std.sx";
+
+Drawable :: protocol {
+    draw :: () -> s32;
+    name :: () -> string;
+    layout :: (x: s32) -> s32;
+    handle :: (event: s32) -> bool;
+}
+
+Circle :: struct { radius: s32; }
+impl Drawable for Circle {
+    draw :: (self: *Circle) -> s32 { self.radius; }
+    name :: (self: *Circle) -> string { "circle"; }
+    layout :: (self: *Circle, x: s32) -> s32 { x + self.radius; }
+    handle :: (self: *Circle, event: s32) -> bool { event > 0; }
+}
+
+Square :: struct { side: s32; }
+impl Drawable for Square {
+    draw :: (self: *Square) -> s32 { self.side * self.side; }
+    name :: (self: *Square) -> string { "square"; }
+    layout :: (self: *Square, x: s32) -> s32 { x + self.side; }
+    handle :: (self: *Square, event: s32) -> bool { event > 1; }
+}
+
+Rect :: struct {
+    x: f32;
+    y: f32;
+    w: f32;
+    h: f32;
+    zero :: () -> Rect { Rect.{ x = 0.0, y = 0.0, w = 0.0, h = 0.0 }; }
+}
+
+Container :: struct {
+    child: Drawable;
+    computed_frame: Rect = .zero();
+}
+
+// Two different structs, each with List(Container), both calling .append(.{...})
+// This mirrors VStack/HStack in the game.
+
+StackA :: struct {
+    children: List(Container);
+
+    add :: (self: *StackA, d: Drawable) {
+        // BUG: `.{ child = d }` causes LLVM error when 2+ structs do this
+        self.children.append(.{ child = d });
+    }
+}
+
+StackB :: struct {
+    children: List(Container);
+
+    add :: (self: *StackB, d: Drawable) {
+        // BUG: second struct doing `.{ child = d }` triggers the error
+        self.children.append(.{ child = d });
+        // FIX: explicit `Container.{ child = d }` works
+        // self.children.append(Container.{ child = d });
+    }
+}
+
+main :: () -> void {
+    c := Circle.{ radius = 42 };
+    s := Square.{ side = 5 };
+
+    a : StackA = .{};
+    a.add(c);
+    print("StackA: draw={}\n", a.children.items[0].child.draw());
+
+    b : StackB = .{};
+    b.add(s);
+    print("StackB: draw={}\n", b.children.items[0].child.draw());
+
+    print("OK\n");
+}