Integer part of a float

[Kostis Sagonas]

I am looking for a built-in function that returns the integer
part of a (positive) float, something like floor/1, and although
I've spent quite some time looking for this, I cannot find it,

Is it true that there there is no built-in like that?

Kostis.

PS. I know I can write it myself by float_to_list, search for "."
    and then do list_to_integer but I am surprised that I could not
    find this as a built-in.