I need to code a float with magnitude (ie unit of measure)

I'm apologize about my poor english

I need to a "double precision" with magniude (ie meters, kilo, dolar,
etc). And can operate with them (ie dolar+dolar=dolar or
dolar/dolar=double precision).

Do you know some pluggin or module to do this?

I can implement it but I need some examples. I try the example of
chapter "User-Defined Types" but I don't know how to compile in windows
(with MinGW). I just try some thigns that breaks postgres.exe.

Can you send me an example (with c code and makefile to see how to
compile). Simple example is ok. The Manual example is not enaugh
complete for me.

Thanks

Emilio Platzer
PD �Do you like to send yo some of my experiments?