
  [;1m-spec float(Number) -> float() when Number :: number().[0m

  Returns a float by converting [;;4mNumber[0m to a float.

  For example:

    > float(55).
    55.0

  [;;4mNote[0m

    If used on the top level in a guard, it tests whether the
    argument is a floating point number; for clarity, use [;;4m[0m
    [;;4mis_float/1[0m instead. When [;;4mfloat/1[0m is used in an expression
    in a guard, such as '[;;4mfloat(A) == 4.0[0m', it converts a number
    as described earlier.
