Use std::numeric_limits<T> to query various properties of a numeric type T:

• Use min() and max() static methods to get the smallest and largest finite numbers of a type:

        template<typename T, typename I> 
        T minimum(I const start, I const end) 
        { 
          T minval = std::numeric_limits<T>::max(); 
          for (auto i = start; i < end; ++i) 
          { 
            if (*i < minval) 
              minval = *i; 
          } 
          return minval; 
        } 

        int range[std::numeric_limits<char>::max() + 1] = { 0 }; 

        switch(get_value()) 
        { 
          case std::numeric_limits<int>::min(): 
          break; 
        }

• Use other static methods and static constants to retrieve other properties of a numeric type:

        auto n = 42; 
        std::bitset<std::numeric_limits<decltype(n)>::digits>  
          bits { static_cast<unsigned long long>(n) };