PhotoCalib has a
Quantity Measurement, which is a simple Struct containing a value and its error, as that's clearer than dealing with a std::pair or tuple. This seems like a useful thing to have more generically (including vectorized versions and maybe a templated version that can manage Point s etc.), but it's not clear where it should live. We probably need something like lsst.primitives for such things (it's not really an afw.geom or an afw.math, it's lower than both).
I've filed this on base, mostly because I'm not sure where else to put it. I don't think this needs an RFC, but I wanted to file a ticket so it doesn't get forgotten (I wasn't going to do the work to lift it somewhere as part of