error feature ID is not a number if it is numeric but not an mvt_double is confusing and possibly incorrect

[dzfranklin]

I got Warning: Attribute "id"="2568923" as feature ID is not a number. This error message initially made me think I was emitting string feature IDs.

From reading the source I believe this error occurs whenever the column type is not an mvt_double:

tippecanoe/serial.cpp

Line 808 in 51fcf14

fprintf(stderr, "Warning: Attribute \"%s\"=\"%s\" as feature ID is not a number\n", sf.full_keys[i].c_str(), sf.full_values[i].s.c_str());

In my case this came from a flatgeobuf uint column: https://github.com/felt/tippecanoe/blob/51fcf142df1ba33e5d0a6ae6ebc57bae47d0fca3/flatgeobuf.cpp#L200C1-L200C56

Is the expected usage that I should be emitting floating point feature IDs? Instinctively that feels wrong because I have never seen non-integer feature IDs used.

[e-n-f]

Thanks. I think this is a bug in the flatgeobuf code, since tippecanoe frontends should treat integer and floating point inputs as equivalent. I'll take a look.