{"id":427466,"date":"2024-07-26T09:01:07","date_gmt":"2024-07-26T09:01:07","guid":{"rendered":"http:\/\/savepearlharbor.com\/?p=427466"},"modified":"-0001-11-30T00:00:00","modified_gmt":"-0001-11-29T21:00:00","slug":"","status":"publish","type":"post","link":"https:\/\/savepearlharbor.com\/?p=427466","title":{"rendered":"\u0418\u0433\u0440\u0443\u0448\u0435\u0447\u043d\u0430\u044f \u0438\u043c\u043b\u0435\u043c\u0435\u043d\u0442\u0430\u0446\u0438\u044f \u0447\u0438\u0441\u0435\u043b \u0441 \u0444\u0438\u043a\u0441\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u043e\u0439 \u0442\u043e\u0447\u043a\u043e\u0439 \u0432 C++<\/span>"},"content":{"rendered":"
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\u0412 C++ \u043d\u0435\u0442 \u0431\u0430\u0437\u043e\u0432\u043e\u0433\u043e \u0442\u0438\u043f\u0430 \u0447\u0438\u0441\u0435\u043b \u0441 \u0444\u0438\u043a\u0441\u0438\u0440\u043e\u0432\u0430\u043d\u043d\u043e\u0439 \u0442\u043e\u0447\u043a\u043e\u0439<\/a>, \u0432 \u0441\u0442\u0430\u043d\u0434\u0430\u0440\u0442\u043d\u043e\u0439 \u0431\u0438\u0431\u043b\u0438\u043e\u0442\u0435\u043a\u0435 \u0442\u0430\u043a\u0436\u0435 \u043d\u0435\u0442 \u043a\u043b\u0430\u0441\u0441\u043e\u0432 \u0434\u043b\u044f \u043d\u0438\u0445. \u0412 \u0442\u043e\u0436\u0435 \u0432\u0440\u0435\u043c\u044f \u0440\u0430\u0431\u043e\u0442\u0430 \u0441 \u0447\u0438\u0441\u043b\u0430\u043c\u0438 \u0441 \u043f\u043b\u0430\u0432\u0430\u044e\u0449\u0435\u0439 \u0442\u043e\u0447\u043a\u043e\u0439 (double, float) \u0447\u0430\u0441\u0442\u043e \u043c\u043e\u0436\u0435\u0442 \u0431\u044b\u0442\u044c \u043d\u0435\u043e\u0447\u0435\u0432\u0438\u0434\u043d\u0430 (\u043d\u0430\u043f\u0440\u0438\u043c\u0435\u0440, \u043e\u0442\u0432\u0435\u0442\u044c\u0442\u0435 \u043d\u0430 \u0432\u043e\u043f\u0440\u043e\u0441: \u0430\u0441\u0441\u043e\u0446\u0438\u0430\u0442\u0438\u0432\u043d\u0430 \u043b\u0438 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u044f \u0441\u043b\u043e\u0436\u0435\u043d\u0438\u044f \u043d\u0430\u0434 \u043d\u0438\u043c\u0438?), \u0432\u0434\u043e\u0431\u0430\u0432\u043e\u043a \u044f\u0437\u044b\u043a \u043f\u0440\u0435\u0434\u043e\u0441\u0442\u0430\u0432\u043b\u044f\u0435\u0442 (\u0447\u0430\u0441\u0442\u043e \u043a\u0440\u0438\u0442\u0438\u043a\u0443\u0435\u043c\u0443\u044e) \u0432\u043e\u0437\u043c\u043e\u0436\u043d\u043e\u0441\u0442\u044c \u043f\u0435\u0440\u0435\u0433\u0440\u0443\u0437\u043a\u0438 \u0430\u0440\u0438\u0444\u043c\u0438\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0445 \u043e\u043f\u0435\u0440\u0430\u0442\u043e\u0440\u043e\u0432, \u043f\u043e\u0434\u0442\u0430\u043b\u043a\u0438\u0432\u0430\u044f \u043d\u0430\u0441 \u043a \u0441\u043e\u0437\u0434\u0430\u043d\u0438\u044e \u0441\u043e\u0431\u0441\u0442\u0432\u0435\u043d\u043d\u043e\u0433\u043e \u0442\u0438\u043f\u0430 \u0434\u0430\u043d\u043d\u044b\u0445.<\/p>\n

\u041f\u0440\u0435\u0436\u0434\u0435 \u0447\u0435\u043c \u043f\u0438\u0441\u0430\u0442\u044c \u043a\u043e\u0434, \u0434\u0430\u0432\u0430\u0439\u0442\u0435 \u043f\u043e\u0432\u0442\u043e\u0440\u0438\u043c \u043c\u0430\u0442. \u0447\u0430\u0441\u0442\u044c, \u0430 \u0438\u043c\u0435\u043d\u043d\u043e \u043e \u043f\u0440\u0435\u0434\u0441\u0442\u0430\u0432\u043b\u0435\u043d\u0438\u0435 \u0447\u0438\u0441\u0435\u043b \u0432 \u0442\u0438\u043f\u0430\u0445 uint8_t, int8_t \u0438 \u043e\u0441\u043e\u0431\u0435\u043d\u043d\u043e\u0441\u0442\u044f\u0445 \u0430\u0440\u0438\u0444\u043c\u0438\u0442\u0438\u0447\u0435\u0441\u043a\u0438\u0445 \u043e\u043f\u0435\u0440\u0430\u0446\u0438\u044f\u0445 \u043d\u0430\u0434 \u043d\u0438\u043c\u0438. \u0418\u0442\u0430\u043a, \u0441\u043b\u043e\u0436\u0435\u043d\u0435\u043d\u0438\u0435 \u0434\u0432\u0443\u0445 uint8_t \u043f\u0440\u043e\u0438\u0441\u0445\u043e\u0434\u0438\u0442 \u043f\u043e \u043c\u043e\u0434\u0443\u043b\u044e 256, \u0442\u043e \u0435\u0441\u0442\u044c 1+2 = 3, \u043d\u043e 1 + 255 = 0, \u0434\u043b\u044f int8_t \u043e\u0442\u0440\u0438\u0446\u0430\u0442\u0435\u043b\u044c\u043d\u044b\u0435 \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u044f \u043c\u043e\u0436\u043d\u043e \u0432\u0432\u0435\u0441\u0442\u0438 \u0441\u043b\u0435\u0434\u0443\u0449\u0438\u043c \u043e\u0431\u0440\u0430\u0437\u043e\u043c: \u043e\u0442\u0440\u0438\u0446\u0430\u0442\u0435\u043b\u044c\u043d\u044b\u0435 \u0447\u0438\u0441\u043b\u0430 \u0441\u043e\u043e\u0442\u0432\u0435\u0442\u0441\u0432\u0443\u044e\u0442 \u0442\u0435\u043c \u0431\u0435\u0437\u043d\u0430\u043a\u043e\u0432\u044b\u043c \u0447\u0438\u0441\u043b\u0430\u043c \u0438\u0437 uint8_t \u043a\u043e\u0442\u043e\u0440\u044b\u0435 \u0441\u043a\u043b\u0430\u0434\u044b\u0432\u0430\u044f\u0441\u044c \u043f\u043e \u043c\u043e\u0434\u0443\u043b\u044e 256 \u0434\u0430\u0434\u0443\u0442 \u043d\u043e\u043b\u044c, \u0442\u043e \u0435\u0441\u0442\u044c -1 \u0431\u0443\u0434\u0435\u043c \u0432 \u043f\u0430\u043c\u044f\u0442\u0438 \u0432\u044b\u0433\u043b\u044f\u0434\u0438\u0442\u044c \u043a\u0430\u043a 255 (FF). \u0413\u0440\u0430\u043d\u0438\u0446\u044b \u0442\u0438\u043f\u0430 int8_t -128…+127, \u0434\u043b\u044f \u043e\u0442\u0440\u0438\u0446\u0430\u0442\u0435\u043b\u044c\u043d\u044b\u0445 \u0447\u0438\u0441\u0435\u043b \u0441\u0442\u0430\u0440\u0448\u0438\u0439 \u0431\u0438\u0442 \u0432\u0441\u0435\u0433\u0434\u0430 \u0440\u0430\u0432\u0435\u043d 1. \u041f\u0440\u0438 \u0443\u043c\u043d\u043e\u0436\u0435\u043d\u0438\u0438 \u0434\u0432\u0443\u0445 int8_t \u043f\u043e\u043b\u0443\u0447\u0430\u0435\u043c \u0440\u0435\u0437\u0443\u043b\u044c\u0442\u0430\u0442 \u0442\u0438\u043f\u0430 int16_t, \u0447\u0430\u0441\u0442\u043d\u043e\u0435 \u043e\u0442 \u0434\u0435\u043b\u0435\u043d\u0438\u044f int16_t \u043d\u0430 uint8_t \u0431\u0443\u0434\u0435\u0442 \u0438\u043c\u0435\u0442\u044c \u0442\u0438\u043f uint8_t. \u0412\u0441\u0435 \u044d\u0442\u0438 \u0441\u0432\u0435\u0434\u0435\u043d\u0438\u044f \u043d\u043e\u0441\u044f\u0442 \u0430\u0431\u043e\u043b\u044e\u0442\u043d\u043e \u0442\u0440\u0438\u0432\u0438\u0430\u043b\u044c\u043d\u044b\u0439 \u0445\u0430\u0440\u0430\u043a\u0442\u0435\u0440, \u043d\u043e, \u043e\u043d\u0438 \u043d\u0435\u043e\u0431\u0445\u043e\u0434\u0438\u043c\u044b \u0434\u043b\u044f \u0434\u0430\u043b\u044c\u043d\u0435\u0439\u0448\u0435\u0433\u043e \u043f\u043e\u043d\u0438\u043c\u0430\u043d\u0438\u044f \u0441\u0442\u0430\u0442\u044c\u0438.<\/p>\n

\u0418\u0442\u0430\u043a, \u043f\u0435\u0440\u0435\u0439\u0434\u0451\u043c \u043a \u043e\u0441\u043d\u043e\u0432\u043d\u043e\u0439 \u0438\u0434\u0435\u0435: \u0447\u0442\u043e \u0435\u0441\u043b\u0438 \u043c\u044b \u043c\u044b\u0441\u043b\u0435\u043d\u043d\u043e \u0432\u043e\u0437\u044c\u043c\u0435\u043c \u0437\u043d\u0430\u0447\u0435\u043d\u0438\u0435 \u0442\u0438\u043f\u0430 int8_t \u0438 \u0441\u043a\u0430\u0436\u0435\u043c, \u0447\u0442\u043e \u0442\u0435\u043f\u0435\u0440\u044c \u044d\u0442\u043e \u043d\u0435 \u0447\u0438\u0441\u043b\u043e \u0435\u0434\u0438\u043d\u0438\u0446, \u0430 \u0441\u043a\u0430\u0436\u0435\u043c, \u0447\u0438\u0441\u043b\u043e 1\/4 (\u043f\u0440\u043e\u0433\u043e\u0432\u043e\u0440\u0438\u043c \u0441\u043b\u043e\u0432\u0430\u043c\u0438: \u044d\u0442\u043e \u0447\u0438\u0441\u043b\u043e \u043f\u043e\u043a\u0430\u0437\u044b\u0432\u0430\u0435\u0442 \u0441\u043a\u043e\u043b\u044c\u043a\u043e \u0447\u0435\u0442\u0432\u0435\u0440\u0442\u044b\u0445 \u0447\u0430\u0441\u0442\u0435\u0439 \u0432 \u0438\u0441\u0445\u043e\u0434\u043d\u043e\u043c \u0447\u0438\u0441\u043b\u0435)? \u041f\u043e\u0441\u043b\u0435 \u0447\u0435\u0433\u043e \u0438\u043d\u043a\u0430\u043f\u0441\u0443\u043b\u0438\u0440\u0443\u0435\u043c \u044d\u0442\u0443 \u043f\u0435\u0440\u043c\u0435\u043d\u043d\u0443\u044e \u0432 \u043f\u043e\u043b\u0435 \u043a\u043b\u0430\u0441\u0441\u0430 \u0438 \u043f\u0435\u0440\u0435\u0433\u0440\u0443\u0437\u0438\u043c \u0434\u043b\u044f \u043d\u0435\u0433\u043e \u043e\u0441\u043d\u043e\u0432\u043d\u044b\u0435 \u0430\u0440\u0438\u0444\u043c\u0438\u0442\u0438\u0447\u0435\u043a\u0438\u0435 \u043e\u043f\u0435\u0440\u0430\u0442\u043e\u0440\u044b \u0438 \u043d\u0430\u043f\u0438\u0448\u0435\u043c \u0441\u0432\u043e\u0439 operator string() \u0434\u043b\u044f \u043f\u0440\u0430\u0432\u0438\u043b\u044c\u043d\u043e\u0433\u043e \u0432\u044b\u0432\u043e\u0434\u0430 \u0442\u0430\u043a\u0438\u0445 \u0447\u0438\u0441\u0435\u043b. \u041d\u0438\u0436\u0435, \u043c\u043e\u0436\u043d\u043e \u043f\u043e\u0441\u043c\u043e\u0442\u0440\u0435\u0442\u044c, \u0447\u0442\u043e \u043f\u043e\u043b\u0443\u0447\u0430\u0435\u0442\u0441\u044f \u0438\u0437 \u044d\u0442\u043e\u0439 \u0438\u0434\u0435\u0438.<\/p>\n

#include <stdexcept> #include <cmath> #include <climits> #include <iostream> #include <sstream> #include <iomanip>  template <typename T> constexpr T ipow(T num, unsigned int pow) {     return (pow >= sizeof(unsigned int)*8) ? 0 :                pow == 0 ? 1 : num * ipow(num, pow-1); }  \/\/ fills and return given number of ones in the least significant bits of a byte constexpr uint8_t mask(uint8_t num) {     return num == 0 ? 0 : (mask(num - 1) << 1) | 1; }  \/\/ FractionLength - how many bits are after a period template <uint8_t FractionLength> class FixedPoint { public:      explicit FixedPoint(int decimal, unsigned int fraction = 0): val(0)     {         if (decimal > max_dec || decimal < min_dec || (decimal == min_dec && fraction) || (fraction >= full_fraction))         {             throw std::invalid_argument(\"It won't fit our so few bits\");         }          int8_t sign = decimal > 0 ? +1 : -1;          val |= fraction;         val |= (decimal << FractionLength);         val *= sign;     }      explicit FixedPoint(double v): val(0)     {         double decimal_double = 0.0;         double fraction = std::modf(v, &decimal_double);          if (decimal_double > max_dec || decimal_double < min_dec)         {             throw std::invalid_argument(\"It won't fit our so few bits\");         }          int8_t decimal_part = static_cast<int8_t>(decimal_double);         int8_t sign = v > 0 ? +1 : -1;         decimal_part = std::abs(decimal_part);          uint32_t fraction_decimal = std::abs(fraction)* ipow(10, FractionLength + 1);         uint8_t count = fraction_decimal \/ fraction_unit_halv;         count += count & 0x01;         count >>= 1;          if (count && sign == -1 && decimal_part == min_dec_abs)         {             throw std::invalid_argument(\"It won't fit our so few bits\");         }          if (count == full_fraction)         {             decimal_part += 1;              auto decimal_part_signed = sign * decimal_part;              if (decimal_part_signed > max_dec || decimal_part_signed < min_dec)             {                 throw std::invalid_argument(\"It won't fit our so few bits\");             }         }         else         {             val |= count;         }          val |= (decimal_part << FractionLength);          val *= sign;      }       FixedPoint operator + (const FixedPoint& r) const     {         return makeFx(val + r.val);     }      FixedPoint operator - (const FixedPoint& r) const     {         return makeFx(val - r.val);     }      FixedPoint operator - () const     {         return makeFx(-val);     }      FixedPoint operator * (const FixedPoint& r) const     {         uint16_t temp = val * r.val;         temp >>= (FractionLength - 1);         uint8_t unit = temp & 0x01;          return makeFx((temp >> 1) + unit);     }      FixedPoint operator \/ (const FixedPoint& r) const     {         uint16_t left = val;         left <<= (FractionLength + 1);         uint8_t temp = left \/ r.val;         uint8_t unit = temp & 0x01;          return makeFx((temp >> 1) + unit );     }      operator std::string() const     {         std::stringstream res;         uint8_t temp = val;         auto fraction = temp & fraction_mask;          if (sign_mask & temp)         {             res << '-';              temp = ~temp + 1;             fraction = temp & fraction_mask;         }          res << (temp >> FractionLength);           if (fraction)         {             res << '.' << std::setw(FractionLength) << fraction * fraction_unit;         }          return res.str();     }  private:      int8_t val;     static constexpr uint8_t decimal_lenght = CHAR_BIT - FractionLength;     static constexpr uint8_t max_dec = (1 << (decimal_lenght - 1)) - 1;     static constexpr int8_t  min_dec_abs = (1 << (decimal_lenght - 1));     static constexpr int8_t  min_dec = -min_dec_abs;     static constexpr uint32_t fraction_unit = ipow(10, FractionLength) \/ (1 << FractionLength);     static constexpr uint32_t fraction_unit_halv = ipow(10, FractionLength + 1) \/ (1 << (FractionLength + 1));     static constexpr uint8_t full_fraction = ipow(2, FractionLength);     static constexpr uint8_t sign_mask = 0x80;     static constexpr uint8_t fraction_mask = mask(FractionLength);     static constexpr uint8_t decimal_mask = 0xFF & ~FractionLength;       explicit FixedPoint(): val(0)     {     }          static FixedPoint makeFx(int8_t v)     {         FixedPoint fp;         fp.val = v;         return fp;     } };  template <uint8_t FractionLength> std::ostream& operator << (std::ostream& out, const FixedPoint<FractionLength>& number) {     out << std::string(number);      return out; }  template <uint8_t FractionLength> const FixedPoint<FractionLength> operator + (const FixedPoint<FractionLength>& l, int r) {     return l + FixedPoint<FractionLength>(r); }  template <uint8_t FractionLength> const FixedPoint<FractionLength> operator + (int l, const FixedPoint<FractionLength>& r) {     return r + FixedPoint<FractionLength>(l); }  template <uint8_t FractionLength> const FixedPoint<FractionLength> operator - (const FixedPoint<FractionLength>& l, int r) {     return l - FixedPoint<FractionLength>(r); }  template <uint8_t FractionLength> const FixedPoint<FractionLength> operator - (int l, const FixedPoint<FractionLength>& r) {     return r - FixedPoint<FractionLength>(l); }  template <uint8_t FractionLength> const FixedPoint<FractionLength> operator * (const FixedPoint<FractionLength>& l, int r) {     return l * FixedPoint<FractionLength>(r); }  template <uint8_t FractionLength> const FixedPoint<FractionLength> operator * (int l, const FixedPoint<FractionLength>& r) {     return r * FixedPoint<FractionLength>(l); }  template <uint8_t FractionLength> const FixedPoint<FractionLength> operator \/ (const FixedPoint<FractionLength>& l, int r) {     return l \/ FixedPoint<FractionLength>(r); }  template <uint8_t FractionLength> const FixedPoint<FractionLength> operator *= (FixedPoint<FractionLength>& l, const FixedPoint<FractionLength>& r) {     l = l * r;     return l; }  template <uint8_t FractionLength> const FixedPoint<FractionLength> operator += (FixedPoint<FractionLength>& l, const FixedPoint<FractionLength>& r) {     l = l + r;     return l; }  using FixedPoint_2 = FixedPoint<2>; using FixedPoint_4 = FixedPoint<4>; <\/code><\/pre>\n
\u041f\u043e\u044f\u0441\u043d\u0435\u043d\u0438\u044f:<\/p>\n