Variables representing quantities, would you use suffices, types or neither for the units

[jack]

Poll #1872 Variables with units

Open to: Registered Users, detailed results viewable to: All, participants: 11

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Which do you prefer:

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quantity width = 2.0*meters;
0 (0.0%)

int width_m = 2;
4 (36.4%)

int width=2; // meters
9 (81.8%)

int width=2;
3 (27.3%)

Comments

[jack]

That's roughly what I was thinking. Maybe the poll reflects that most people only ever need programs which DO only have one unit in, I'm surprised so few people were more cautious.

I was just editing some code that used a small number of units (mostly period and frequency with different SI prefixes, and in one places tenths of microseconds). And altered it so each variable name included the unit; without that it seemed just a matter of time before a conversion was wrong somewhere.

Maybe what people mean is that it should never have used different units at all, but always used s or Hz, stored floating point. That could be better, and would need much less disambiguation, but having different units without disambiguation seemed the worst of both worlds.

Apparently 75% of people think that comments on variables are actually useful.

I guess that could be, "if you have one unit used throughout the program, you should document it _somewhere_".

Or, come to think of it, "use an editor which displays comments next to variable declarations when you use the variable", in which case it's a superior version of the hungarian annotation.

They probably know better than _me_ :)

You could go for a measurement class that includes the unit,

The coding on the first poll option was screwed up, but it was supposed to be boost::units, which seemed very cumbersome, but is _supposed_ to compile back to ints. I don't know if it will in practice.