v/vlib/v/tests/assert_should_evaluate_args_just_once_test.v

struct Abc {
	ncalls int
}

[unsafe]
fn fn_that_should_be_called_just_once_array() []int {
	mut static ncalls := 0
	ncalls++
	println('${@FN} calls: $ncalls')
	if ncalls > 1 {
		assert false
	}
	return []int{len: ncalls, init: ncalls}
}

[unsafe]
fn fn_that_should_be_called_just_once_struct() Abc {
	mut static ncalls := 0
	ncalls++
	println('${@FN} calls: $ncalls')
	if ncalls > 1 {
		assert false
	}
	return Abc{
		ncalls: ncalls
	}
}

fn test_assert_calls_a_function_returning_an_array_just_once() {
	unsafe {
		assert fn_that_should_be_called_just_once_array().len == 1
	}
}

fn test_assert_calls_a_function_returning_a_struct_just_once() {
	unsafe {
		assert fn_that_should_be_called_just_once_struct().ncalls == 1
	}
}