go-ethereum/accounts/abi/bind/base.go
func (c *BoundContract) UnpackLogIntoMap(out map[string]interface{}, event string, log types.Log) error

go-ethereum/accounts/abi/topics.go
func ParseTopicsIntoMap(out map[string]interface{}, fields Arguments, topics []common.Hash) error

parseTopicWithSetter
if len(fields) != len(topics) {
	return errors.New("topic/field count mismatch")
}