Standard library header <limits>

 

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Technical Specifications

 

Standard Library headers

Language Support
<cstddef> <cstdlib> <version> <limits> <climits>	<cfloat> <cstdint> <new> <typeinfo>	<source_location> <exception> <initializer_list> <compare>	<coroutine> <csignal> <csetjmp> <cstdarg>
Concepts
<concepts>
Diagnostics
<stdexcept>	<cassert>	<cerrno>	<system_error>
General utilities
<utility> <memory> <memory_resource> <scoped_allocator>	<bitset> <tuple> <optional> <any>	<variant> <type_traits> <ratio> <chrono>	<typeindex> <functional> <ctime>
Strings
<string> <string_view> <cstring>	<charconv> <format>	<cctype> <cwctype>	<cwchar> <cuchar>
Localization
<locale>	<codecvt>	<clocale>
Containers
<span> <array> <vector>	<deque> <forward_list> <list>	<map> <set> <queue>	<unordered_map> <unordered_set> <stack>
Iterators
<iterator>
Ranges
<ranges>
Algorithms
<algorithm>	<execution>
Numerics
<complex> <random>	<valarray> <numeric>	<bit> <numbers>	<cfenv> <cmath>
Input/Output
<iosfwd> <ios> <iomanip> <streambuf>	<istream> <ostream> <iostream>	<sstream> <fstream> <syncstream>	<cstdio> <cinttypes> <strstream>
Regular expressions
<regex>
Filesystem support
<filesystem>
Thread support
<thread> <atomic> <mutex>	<shared_mutex> <condition_variable> <future>	<stop_token> <semaphore>	<latch> <barrier>
C compatibility
<ciso646> <cstdalign>	<cstdbool> <ccomplex>	<ctgmath>

 

This header is part of the type support library.

Declarations

numeric_limits	provides an interface to query properties of all fundamental numeric types. (class template)
float_round_style	indicates floating-point rounding modes (enum)
float_denorm_style	indicates floating-point denormalization modes (enum)

Synopsis

namespace std {template<class T>class numeric_limits;   enum float_round_style { round_indeterminate =-1, round_toward_zero =0, round_to_nearest =1, round_toward_infinity =2, round_toward_neg_infinity =3, };   enum float_denorm_style { denorm_indeterminate =-1, denorm_absent =0, denorm_present =1};     template<>class numeric_limits<bool>;   template<>class numeric_limits<char>;template<>class numeric_limits<signedchar>;template<>class numeric_limits<unsignedchar>;template<>class numeric_limits<char8_t>;template<>class numeric_limits<char16_t>;template<>class numeric_limits<char32_t>;template<>class numeric_limits<wchar_t>;   template<>class numeric_limits<short>;template<>class numeric_limits<int>;template<>class numeric_limits<long>;template<>class numeric_limits<longlong>;template<>class numeric_limits<unsignedshort>;template<>class numeric_limits<unsignedint>;template<>class numeric_limits<unsignedlong>;template<>class numeric_limits<unsignedlonglong>;   template<>class numeric_limits<float>;template<>class numeric_limits<double>;template<>class numeric_limits<longdouble>;}

Class template std::numeric_limits

template<class T>class numeric_limits {public:staticconstexprbool is_specialized =false;   staticconstexpr T min()noexcept{return T();}staticconstexpr T max()noexcept{return T();}staticconstexpr T lowest()noexcept{return T();}   staticconstexprint digits =0;staticconstexprint digits10 =0;staticconstexprint max_digits10 =0;   staticconstexprbool is_signed =false;staticconstexprbool is_integer =false;staticconstexprbool is_exact =false;staticconstexprint radix =0;staticconstexpr T epsilon()noexcept{return T();}staticconstexpr T round_error()noexcept{return T();}   staticconstexprint min_exponent =0;staticconstexprint min_exponent10 =0;staticconstexprint max_exponent =0;staticconstexprint max_exponent10 =0;   staticconstexprbool has_infinity =false;staticconstexprbool has_quiet_NaN =false;staticconstexprbool has_signaling_NaN =false;staticconstexpr float_denorm_style has_denorm = denorm_absent;staticconstexprbool has_denorm_loss =false;staticconstexpr T infinity()noexcept{return T();}staticconstexpr T quiet_NaN()noexcept{return T();}staticconstexpr T signaling_NaN()noexcept{return T();}staticconstexpr T denorm_min()noexcept{return T();}   staticconstexprbool is_iec559 =false;staticconstexprbool is_bounded =false;staticconstexprbool is_modulo =false;   staticconstexprbool traps =false;staticconstexprbool tinyness_before =false;staticconstexpr float_round_style round_style = round_toward_zero;   };

Specialization std::numeric_limits<bool>

template<>class numeric_limits<bool>{public:staticconstexprbool is_specialized =true;   staticconstexprbool min()noexcept{returnfalse;}staticconstexprbool max()noexcept{returntrue;}staticconstexprbool lowest()noexcept{returnfalse;}   staticconstexprint digits =1;staticconstexprint digits10 =0;staticconstexprint max_digits10 =0;   staticconstexprbool is_signed =false;staticconstexprbool is_integer =true;staticconstexprbool is_exact =true;staticconstexprint radix =2;staticconstexprbool epsilon()noexcept{return0;}staticconstexprbool round_error()noexcept{return0;}   staticconstexprint min_exponent =0;staticconstexprint min_exponent10 =0;staticconstexprint max_exponent =0;staticconstexprint max_exponent10 =0;   staticconstexprbool has_infinity =false;staticconstexprbool has_quiet_NaN =false;staticconstexprbool has_signaling_NaN =false;staticconstexpr float_denorm_style has_denorm = denorm_absent;staticconstexprbool has_denorm_loss =false;staticconstexprbool infinity()noexcept{return0;}staticconstexprbool quiet_NaN()noexcept{return0;}staticconstexprbool signaling_NaN()noexcept{return0;}staticconstexprbool denorm_min()noexcept{return0;}   staticconstexprbool is_iec559 =false;staticconstexprbool is_bounded =true;staticconstexprbool is_modulo =false;   staticconstexprbool traps =false;staticconstexprbool tinyness_before =false;staticconstexpr float_round_style round_style = round_toward_zero;   };