numeric_ Limits the range and related attributes of each data type learned

c++ There are many data types in , Each data type has a range and related attributes , such as short The type is 16, Range from -32768 To 32767,int The range is from -2147483648 To 2147483647 wait , Because the length of each data type is different , The scope is very different , So I didn't remember their specific scope , and numeric_limits You can view the range size of each data type , It is also convenient to use , Let's look at specific examples ：

Member constants

is_specialized [ static state ]	To identify std::numeric_limits Whether to specialize for this type ( Expose static member constants )
is_signed [ static state ]	Identify signed types ( Expose static member constants )
is_integer [ static state ]	Identify integer types ( Expose static member constants )
is_exact [ static state ]	Identify the type of accurate representation ( Expose static member constants )
has_infinity [ static state ]	Discrimination can represent special values “ Positive infinity ” Floating point type of ( Expose static member constants )
has_quiet_NaN [ static state ]	Discrimination can represent special values “ Quiet non number ”（ NaN ） Floating point type of ( Expose static member constants )
has_signaling_NaN [ static state ]	Discrimination can represent special values “ The number of non letters sent ”（ NaN ） Floating point type of ( Expose static member constants )
has_denorm [ static state ]	The informal style used to identify floating-point types ( Expose static member constants )
has_denorm_loss [ static state ]	Identify whether the floating-point type detects an irregular loss of precision , Not inaccurate results ( Expose static member constants )
round_style [ static state ]	The rounding pattern used to identify the type ( Expose static member constants )
is_iec559 [ static state ]	To identify IEC 559/IEEE 754 Floating point type ( Expose static member constants )
is_bounded [ static state ]	Identify the types that represent finite value sets ( Expose static member constants )
is_modulo [ static state ]	Identify the type of overflow handled by modular arithmetic ( Expose static member constants )
digits [ static state ]	Capable of being represented unchanged radix digit ( Expose static member constants )
digits10 [ static state ]	The number of decimal digits that can be represented unchanged ( Expose static member constants )
max_digits10 [ static state ] (C++11)	The number of decimal digits required to distinguish all values of this type ( Expose static member constants )
radix [ static state ]	The base or integer base used for the representation of a given type ( Expose static member constants )
min_exponent [ static state ]	The power of the base is the smallest negative number plus one of the legal normal floating-point values ( Expose static member constants )
min_exponent10 [ static state ]	10 The power of this number is the minimum negative number of the legal normal floating-point value ( Expose static member constants )
max_exponent [ static state ]	The power of the number of times at the bottom is the maximum integer of the legal finite floating-point value plus one ( Expose static member constants )
max_exponent10 [ static state ]	10 The power of this number is the largest integer of a legal finite floating-point value ( Expose static member constants )
traps [ static state ]	Identify the types that may cause traps in arithmetic operations ( Expose static member constants )
tinyness_before [ static state ]	Identify and detect whether the floating-point type is irregular before rounding ( Expose static member constants )

Member functions

min [ static state ]	Returns the minimum finite value of a given type ( Expose static member functions )
lowest [ static state ] (C++11)	Returns the lowest finite value of a given type ( Expose static member functions )
max [ static state ]	Returns the maximum finite value of a given type ( Expose static member functions )
epsilon [ static state ]	return 1.0 The difference from the next representable value of a given type ( Expose static member functions )
round_error [ static state ]	Returns the maximum rounding error for a given floating-point type ( Expose static member functions )
infinity [ static state ]	Returns a positive infinity value of a given type ( Expose static member functions )
quiet_NaN [ static state ]	Returns the value of the given floating-point type NaN value ( Expose static member functions )
signaling_NaN [ static state ]	Returns the sending of a given floating-point type NaN ( Expose static member functions )
denorm_min [ static state ]	Returns the minimum positive non normal value of a given floating-point type ( Expose static member functions )

Code example ：

#include <iostream>
#include <limits>

using namespace std;

int main()
{
    cout << std::boolalpha;

    std::cout << "type\t\t│ lowest()\t│ min()\t\t│ max()\n";
    std::cout << "bool\t\t│ " << std::numeric_limits<bool>::lowest() << "\t\t│ "
              << std::numeric_limits<bool>::min() << "\t\t│ "
              << std::numeric_limits<bool>::max() << '\n';
    std::cout << "char\t\t│ " << std::numeric_limits<char>::lowest() << "\t\t│ "
              << std::numeric_limits<char>::min() << "\t\t│ "
              << std::numeric_limits<char>::max() << '\n';
    std::cout << "float\t\t│ " << std::numeric_limits<float>::lowest() << "\t│ "
              << std::numeric_limits<float>::min() << "\t│ "
              << std::numeric_limits<float>::max() << '\n';
    std::cout << "double\t\t│ " << std::numeric_limits<double>::lowest() << "\t│ "
              << std::numeric_limits<double>::min() << "\t│ "
              << std::numeric_limits<double>::max() << '\n';
    std::cout << "wchar_t\t\t│ " << std::numeric_limits<wchar_t>::lowest() << "\t\t│ "
              << std::numeric_limits<wchar_t>::min() << "\t\t│ "
              << std::numeric_limits<wchar_t>::max() << '\n';
    std::cout << "char16_t\t│ " << std::numeric_limits<char16_t>::lowest() << "\t\t│ "
              << std::numeric_limits<char16_t>::min() << "\t\t│ "
              << std::numeric_limits<char16_t>::max() << '\n';
    std::cout << "char32_t\t│ " << std::numeric_limits<char32_t>::lowest() << "\t\t│ "
              << std::numeric_limits<char32_t>::min() << "\t\t│ "
              << std::numeric_limits<char32_t>::max() << '\n';
    std::cout << "short\t\t│ " << std::numeric_limits<short>::lowest() << "\t│ "
              << std::numeric_limits<short>::min() << "\t│ "
              << std::numeric_limits<short>::max() << '\n';
    std::cout << "signed short\t│ " << std::numeric_limits<signed short>::lowest() << "\t│ "
              << std::numeric_limits<signed short>::min() << "\t│ "
              << std::numeric_limits<signed short>::max() << '\n';
    std::cout << "unsigned short\t│ " << std::numeric_limits<unsigned short>::lowest() << "\t\t│ "
              << std::numeric_limits<unsigned short>::min() << "\t\t│ "
              << std::numeric_limits<unsigned short>::max() << '\n';
    std::cout << "int\t\t│ " << std::numeric_limits<int>::lowest() << "\t│ "
              << std::numeric_limits<int>::min() << "\t│ "
              << std::numeric_limits<int>::max() << '\n';
    std::cout << "signed int\t│ " << std::numeric_limits<signed int>::lowest() << "\t│ "
              << std::numeric_limits<signed int>::min() << "\t│ "
              << std::numeric_limits<signed int>::max() << '\n';
    std::cout << "unsigned int\t│ " << std::numeric_limits<unsigned int>::lowest() << "\t\t│ "
              << std::numeric_limits<unsigned int>::min() << "\t\t│ "
              << std::numeric_limits<unsigned int>::max() << '\n';
    std::cout << "long\t\t│ " << std::numeric_limits<long>::lowest() << "\t│ "
              << std::numeric_limits<long>::min() << "\t│ "
              << std::numeric_limits<long>::max() << '\n';
    std::cout << "signed long\t│ " << std::numeric_limits<signed long>::lowest() << "\t│ "
              << std::numeric_limits<signed long>::min() << "\t│ "
              << std::numeric_limits<signed long>::max() << '\n';
    std::cout << "unsigned long\t│ " << std::numeric_limits<unsigned long>::lowest() << "\t\t│ "
              << std::numeric_limits<unsigned long>::min() << "\t\t│ "
              << std::numeric_limits<unsigned long>::max() << '\n';
    std::cout << "long long\t│ " << std::numeric_limits<long long>::lowest() << "\t\t│ "
              << std::numeric_limits<long long>::min() << "\t\t│ "
              << std::numeric_limits<long long>::max() << '\n';
    std::cout << "signed long long│ " << std::numeric_limits<signed long long>::lowest() << "\t\t│ "
              << std::numeric_limits<signed long long>::min() << "\t\t│ "
              << std::numeric_limits<signed long long>::max() << '\n';
    std::cout << "unsigned long long│ " << std::numeric_limits<unsigned long long>::lowest() << "\t\t│ "
              << std::numeric_limits<unsigned long long>::min() << "\t\t│ "
              << std::numeric_limits<unsigned long long>::max() << '\n';

    cout << "Hello World!" << endl;
    return 0;
}

Running results ：

 

Reference resources ：

std::numeric_limits - cppreference.com

https://cplusplus.com/reference/limits/numeric_limits/