-> !!(obj and obj.getTimezoneOffset and obj.setUTCFullYear)


# Is the given value a regular expression?
_.isRegExp = (obj) -> !!(obj and obj.exec and (obj.ignoreCase or obj.ignoreCase is false))


# Is the given value NaN -- this one is interesting. `NaN != NaN`, and
# `isNaN(undefined) == true`, so we make sure it's a number first.
_.isNaN = (obj) -> _.isNumber(obj) and window.isNaN(obj)


# Is a given value equal to null?
_.isNull = (obj) -> obj is null


# Is a given variable undefined?
_.isUndefined = 