v.gen.c: fix generics array delete (#11429)

vlib/v/gen/c/fn.v

@@ -749,6 +749,18 @@ fn (mut g Gen) method_call(node ast.CallExpr) {
 		g.expr(node.args[0].expr)
 		g.write('})')
 		return
+	} else if left_sym.kind == .array && node.name == 'delete' {
+		g.write('array_delete(')
+		if node.left_type.is_ptr() {
+			g.expr(node.left)
+		} else {
+			g.write('&')
+			g.expr(node.left)
+		}
+		g.write(', ')
+		g.expr(node.args[0].expr)
+		g.write(')')
+		return
 	}
 
 	if left_sym.kind in [.sum_type, .interface_] {

vlib/v/tests/generics_array_delete_test.v

@@ -0,0 +1,48 @@
+struct Set<T> {
+mut:
+	field []T
+}
+
+fn (mut s Set<T>) add<T>(value T) bool {
+	mut result := false
+
+	if value !in s.field {
+		s.field << value
+		result = true
+	}
+
+	return result
+}
+
+fn (mut s Set<T>) remove<T>(value T) bool {
+	mut result := false
+
+	if value in s.field {
+		ndx := s.field.index(value)
+		s.field.delete(ndx)
+		result = true
+	}
+
+	return result
+}
+
+fn test_generics_array_delete() {
+	mut set := Set<int>{}
+
+	mut added := set.add(4)
+	println(added)
+	assert added
+
+	added = set.add(3)
+	println(added)
+	assert added
+
+	added = set.add(3)
+	println(added)
+	assert !added
+
+	println(set)
+	mut removed := set.remove(4)
+	println(removed)
+	assert removed
+}