[foobar1726]

It seems like the C++98 example is the best by far? Keeps all error information while remaining concise and easy to understand. Not to mention 50 times faster. (Could be improved by adding some simple type aliases like BirthYear that explicitly start from 1900.)

IMO the main takeaway is that malformed input is not an exceptional state when parsing, and should be treated as a first class citizen. Everything else is yak shaving how you want to handle the (status, validObject) tuple coming from the parser.

[philip-b]

The compile time is 50 times faster, not the runtime.