std::numeric_limits<T>::min

 

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Defined in header <limits>
static T min() throw();		(until C++11)
static constexpr T min() noexcept;		(since C++11)

Returns the minimum finite value representable by the numeric type T.

For floating-point types with denormalization, min() returns the minimum positive normalized value. Note that this behavior may be unexpected, especially when compared to the behavior of min() for integral types. To find the value that has no values less than it, use lowest().(since C++11)

min() is only meaningful for bounded types and for unbounded unsigned types.

Return value

T	std::numeric_limits<T>::min()
/* non-specialized */	T()
bool	false
char	CHAR_MIN
signed char	SCHAR_MIN
unsigned char	​0​
wchar_t	WCHAR_MIN
char8_t (since C++20)	​0​
char16_t (since C++11)	​0​
char32_t (since C++11)	​0​
short	SHRT_MIN
unsigned short	​0​
int	INT_MIN
unsigned int	​0​
long	LONG_MIN
unsigned long	​0​
long long (since C++11)	LLONG_MIN
unsigned long long (since C++11)	​0​
float	FLT_MIN
double	DBL_MIN
long double	LDBL_MIN

Example

Demonstrates the use with typedef types, and the difference in the sign of the result between integer and floating-point types:

Run this code

#include <cstddef>
#include <iomanip>
#include <iostream>
#include <limits>
 
template <typename T>
void print_one(std::string_view type_name)
{
    using TypeForOutput = std::conditional<sizeof(T) == sizeof(char), int, T>::type;
    constexpr TypeForOutput min = std::numeric_limits<T>::min();
    std::cout 
        << std::dec << std::defaultfloat << std::setw(14) << type_name
        << " (" << std::setw(2) << sizeof(T) << " bytes): " << min;
 
    if constexpr (min != 0)
        std::cout << " or " << std::showbase << std::hex << std::hexfloat << min;
 
    std::cout << '\n';
}
 
#define SHOW(T) print_one<T>(#T)
 
int main()
{
    SHOW(bool);
    SHOW(char);
    SHOW(unsigned char);
    SHOW(short);
    SHOW(unsigned short);
    SHOW(signed);
    SHOW(unsigned);
    SHOW(std::ptrdiff_t);
    SHOW(std::size_t);
    SHOW(float);
    SHOW(double);
    SHOW(long double);
}

Possible output:

          bool ( 1 bytes): 0
          char ( 1 bytes): -128 or 0xffffff80
 unsigned char ( 1 bytes): 0
         short ( 2 bytes): -32768 or 0x8000
unsigned short ( 2 bytes): 0
        signed ( 4 bytes): -2147483648 or 0x80000000
      unsigned ( 4 bytes): 0
std::ptrdiff_t ( 8 bytes): -9223372036854775808 or 0x8000000000000000
   std::size_t ( 8 bytes): 0
         float ( 4 bytes): 1.17549e-38 or 0x1p-126
        double ( 8 bytes): 2.22507e-308 or 0x1p-1022
   long double (16 bytes): 3.3621e-4932 or 0x8p-16385

See also

lowest [static] (C++11)	returns the lowest finite value of the given type (public static member function)
denorm_min [static]	returns the smallest positive subnormal value of the given floating-point type (public static member function)
max [static]	returns the largest finite value of the given type (public static member function)