INT_[MIN|MAX] limit macros vs numeric_limits<T>
The other answers mostly have correct information, but it seems that this needs updating for C++11.
In C++11, std::numeric_limits<T>::min()
, std::numeric_limits<T>::max()
, and std::numeric_limits<T>::lowest()
are all declared constexpr
, so they can be usable in most of the same contexts as INT_MIN
and company. The only exception I can think of is compile-time string processing using the #
stringification token.
This means that numeric_limits
can be used for case labels, template parameters, etc., and you get the benefit of using it in generic code (try using INT_MIN
vs. LONG_MIN
in template<typename T> get_min(T t);
).
C++11 also brings a solution to the issue James Kanze talks about, by adding std::numeric_limits<T>::lowest()
, which gives the lowest finite value for all types, rather than the lowest value for integer types and the lowest positive value for floating-point types.
Pre C++0x, definitely. INT_MIN
and INT_MAX
are integral constant expressions; numeric_limits<int>::min()
and numeric_limits<int>::max()
aren't. <climits>
is standard C++, and unless you're dealing with templates (where you don't know whether it's int
or long
), there's really no reason to bother with the overly complicated solution. (Also: if you're writing templates, don't forget that numeric_limits<int>::min()
and numeric_limits<double>::min()
represent completely different attributes; if you want the minimum possible value, you'll need numeric_limits<T>::is_integer ? numeric_limits<T>::min() : -numeric_limits<T>::max()
.)
If C++, use numeric_limits
, end of.
EDIT: Okay, per the comment by James, not "end of." - exceptions are templates and case labels. But, I cannot see a use for having a case label for either min or max, or a template for them, but I guess I've not seen all possibilities...
I guess my point is that the numeric_limits
template is more useful beyond max()
and min()
...