cgen,checker: fix map generic fn arg passing

vlib/v/checker/fn.v

@@ -1723,7 +1723,6 @@ fn (mut c Checker) resolve_comptime_args(func ast.Fn, node_ ast.CallExpr, concre
 						if ctyp != ast.void_type {
 							arg_sym := c.table.final_sym(call_arg.typ)
 							param_typ_sym := c.table.sym(param_typ)
-
 							if param_typ.has_flag(.variadic) {
 								ctyp = ast.mktyp(ctyp)
 								comptime_args[k] = ctyp
@@ -1756,11 +1755,19 @@ fn (mut c Checker) resolve_comptime_args(func ast.Fn, node_ ast.CallExpr, concre
 								cparam_type_sym := c.table.sym(c.unwrap_generic(ctyp))
 								if param_typ_sym.kind == .array && cparam_type_sym.info is ast.Array {
 									comptime_args[k] = cparam_type_sym.info.elem_type
-								} else if param_typ_sym.kind == .map
+								} else if param_typ_sym.info is ast.Map
 									&& cparam_type_sym.info is ast.Map {
-									comptime_args[k] = cparam_type_sym.info.key_type
-									comptime_args[k + 1] = cparam_type_sym.info.value_type
-									k++
+									key_is_generic := param_typ_sym.info.key_type.has_flag(.generic)
+									if key_is_generic {
+										comptime_args[k] = cparam_type_sym.info.key_type
+									}
+									if param_typ_sym.info.value_type.has_flag(.generic) {
+										k2 := if key_is_generic { k + 1 } else { k }
+										comptime_args[k2] = cparam_type_sym.info.value_type
+										if key_is_generic {
+											k++
+										}
+									}
 								} else {
 									if node_.args[i].expr.is_auto_deref_var() {
 										ctyp = ctyp.deref()

vlib/v/gen/c/fn.v

@@ -1343,11 +1343,21 @@ fn (mut g Gen) resolve_comptime_args(func ast.Fn, mut node_ ast.CallExpr, concre
 								cparam_type_sym := g.table.sym(g.unwrap_generic(ctyp))
 								if param_typ_sym.kind == .array && cparam_type_sym.info is ast.Array {
 									comptime_args[k] = cparam_type_sym.info.elem_type
-								} else if param_typ_sym.kind == .map
+								} else if param_typ_sym.info is ast.Map
 									&& cparam_type_sym.info is ast.Map {
-									comptime_args[k] = cparam_type_sym.info.key_type
-									comptime_args[k + 1] = cparam_type_sym.info.value_type
-									k++
+									key_is_generic := param_typ_sym.info.key_type.has_flag(.generic)
+									println(param_typ_sym)
+									println(cparam_type_sym)
+									if key_is_generic {
+										comptime_args[k] = cparam_type_sym.info.key_type
+									}
+									if param_typ_sym.info.value_type.has_flag(.generic) {
+										k2 := if key_is_generic { k + 1 } else { k }
+										comptime_args[k2] = cparam_type_sym.info.value_type
+										if key_is_generic {
+											k++
+										}
+									}
 								} else {
 									if node_.args[i].expr.is_auto_deref_var() {
 										ctyp = ctyp.deref()

vlib/v/tests/comptime_map_part_generic_test.v

@@ -0,0 +1,19 @@
+fn marshal[T](val T) string {
+	return marshal_map(val)
+}
+
+fn marshal_map[T](val map[string]T) string {
+	return typeof(val).name
+}
+
+fn test_main() {
+	assert marshal({
+		'a': 1
+	}) == 'map[string]int'
+	assert marshal({
+		'a': true
+	}) == 'map[string]bool'
+	assert marshal({
+		'a': 1.2
+	}) == 'map[string]f64'
+}