numeric_limits<T>::min();
numeric_limits<T>::lowest();
What is the different between the value returned by both functions?
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Andy Prowl
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Muhammad
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3[For future readers], the table at https://en.cppreference.com/w/cpp/types/numeric_limits, explains it quite well. – dvlper May 20 '20 at 01:59
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Paragraph 18.3.2.4 of the C++11 Standard specifies:
static constexpr T min() noexcept;1 Minimum finite value.
2 For floating types with denormalization, returns the minimum positive normalized value.
3 Meaningful for all specializations
[...]
static constexpr T lowest() noexcept;6 A finite value x such that there is no other finite value y where y < x.
7 Meaningful for all specializations in which is_bounded != false.
Footnote 197 then adds the relevant remark:
lowest()is necessary because not all floating-point representations have a smallest (most negative) value that is the negative of the largest (most positive) finite value.
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Andy Prowl
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in another word `lowest` return something like the 2s complement for maximum positive integer. – Muhammad Apr 03 '13 at 09:35
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4@Muhammadalaa: for integer types there is no difference between `min()` and `lowest()`. – Steve Jessop Apr 03 '13 at 09:57
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For floating point types min returns the smallest finite number that is > 0 representable in the type (i.e. the number having the lowest absolute value != 0) while lowest returns the smallest finite number that is representable (i.e. the negative number of maximal absolute value that is less than -infinity).
filmor
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3The smallest number that is representable is negative infinity; `lowest` give the smallest **finite** representable value. – Pete Becker Apr 03 '13 at 13:29
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If you check a reference of these functions, e.g. this one for min and this one for lowest you can see that there are some values that differ.
Some programmer dude
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