std::numeric_limits<T>:: min

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

Example

#include <cstddef>
#include <iomanip>
#include <iostream>
#include <limits>
 
// we want to print char types as an integer without leading Fs
auto p(auto x) { return x; }
auto p(char x) { return x & static_cast<unsigned char>(-1); }
 
template <typename T>
void print_one(std::string_view type_name)
{
    constexpr T 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 << p(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);
}

          bool ( 1 bytes): 0
          char ( 1 bytes): -128 or 0x80
 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