Smallest positive number possible

Is there a constant in std that represents the smallest positive value that could be represented by a f32 and f64? After looking at the documentation I found f64::MIN_POSITIVE, but if I understand correctly (I know nothing about IEE754), this is just the lowest normal floating point number, and then there are denormal numbers closer to zero (which are still decimal numbers that I can keep adding, multiplying, etc.).

I noticed that I could still divide f32::MIN_POSITIVE by 2 about 24 times before it truncates to 0. Which would make the minimum number 2e-150 (?). But it doesn't == 2e-150f32.

Hopefully my question makes sense.