func main() {
	if x := int(C.F()); x != 1 {
		fatal("x = %d, want 1", x)
	}

	// Open this file itself and verify that the first few characters are
	// as expected.
	f := Fopen("main.go", "r")
	if f.Swigcptr() == 0 {
		fatal("fopen failed")
	}
	if Fgetc(f) != '/' || Fgetc(f) != '/' || Fgetc(f) != ' ' || Fgetc(f) != 'C' {
		fatal("read unexpected characters")
	}
	if Fclose(f) != 0 {
		fatal("fclose failed")
	}