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Comment by tialaramex | Hacker News Reader

Even without Tony Hoare's Billion Dollar Mistake, this sort of nonsense is too easy. Do not define types which unnecessarily have a "default" value when you know there is no meaningful default for the intended type.

This happens way too much for numeric values. "Not applicable" or "None" aren't the same thing as zero, but it is seen for other types too.

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Yes, all the persons in various databases that are born on January 1st 1900 (or 1970) because their birth date is unknown will agree...

Or adding a middle name of “A” because some databases can’t handle that a person might not have a middle name or middle initial.

I have a fairly sophisticated user registration system that can't handle people without family names. We had to jump through some hoops to be able to enroll people who just have given names.

Must have been tough if you rolled out this system in Indonesia.

I'm still irritated about whatever bit or bits of sloppy coding ended up assigning 1/1/1970 as a birthdate for all contacts in my Google account that didn't have a birthdate specified. Combined with birthday notifications and more annoying alerts in older versions of Android or in the browser, it made for annoying New Years Day mornings with several hundred alerts.

Side note: I use 1/1/70 by default when entering birthdays. Only if it's something that I expect to matter - financial or medical institution - do I enter my real birthday.

Entering random dates is not a great idea because I seem to recall one site (Yahoo!, maybe?) insisting on me entering the correct birthday and I had no idea what I put in.

I usually do January 1 <sister's birth year> lol.

Unfortunately most languages make this very difficult to avoid even when you are trying

Golang default type values go brrrrrrr.

Does Go have a way to insist "No, my type doesn't have a default value" ?

The behaviour for the primitive types is at least more rational than C++ (in C++ primitive variables are just uninitialized by default and if read that's Undefined Behaviour, you lose, too bad) but just because my "Position" type has two integers inside it, does not mean that them both being zero constitutes a valid position :/

I don't know how insistent this method is, but you cab create a pointer to a Position, then check if that pointer is nil.

That's pretty unsatisfactory, for the burden of heap allocation your reward is now "null" Positions exist instead of the useless default :/

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