I was woundering if there is some kind of function that returns what is the lowest posible spacing for some variable.

For example, in Fortran you can use function "spacing". Lets say that a variable x is a double (in fortran real :: kind(8) = x). Then spacing(x) would return 2.225073858507201E-308. If for example x was a float, than spacing(x) would give 1.17549435082228E-38. Is there some kind of equivalent to this in c++?