Question

我不擅长str和int之间的转换。

#pragma once

#include <algorithm>
#include <bitset>
#include <cassert>
#include <climits>
#include <cstdint>
#include <exception>
#include <iterator>
#include <iostream>
#include <iomanip>
#include <limits>
#include <type_traits>

namespace vpc {
    using u8  = std::uint8_t;
    using u16 = std::uint16_t;
    using u32 = std::uint32_t;
    using u64 = std::uint64_t;

    template<typename T>
    struct Register;

    using Reg8  = Register<u8>;
    using Reg16 = Register<u16>;
    using Reg32 = Register<u32>;
    using Reg64 = Register<u64>;

    template<typename T>
    struct Register {
        T value;
        std::bitset<sizeof(T)* CHAR_BIT> bits;

        Register() : value{ 0 }, /*previous_value{ 0 },*/ bits{ 0 } {}

        template<typename U, std::enable_if_t<(sizeof(U) > sizeof(T))>* = nullptr>
        explicit Register(const U val, const u8 idx = 0) :
            value{ static_cast<T>((val >> std::size(bits) * idx) &
                  std::numeric_limits<std::make_unsigned_t<T>>::max()) },
            bits{ value }
        {
            constexpr u16 sizeT = sizeof(T);
            constexpr u16 sizeU = sizeof(U);
            assert((idx >= 0) && (idx <= ((sizeU / sizeT) - 1)) );
        }

        template<typename U, std::enable_if_t<(sizeof(U) < sizeof(T))>* = nullptr>
        explicit Register(const U val, const u8 idx = 0) :
            value{ static_cast<T>((static_cast<T>(val) << sizeof(U)*CHAR_BIT*idx) &
                  std::numeric_limits<std::make_unsigned_t<T>>::max()) },
            bits{ value }
        {
            constexpr u16 sizeT = sizeof(T);
            constexpr u16 sizeU = sizeof(U);
            assert((idx >= 0) && (idx <= ((sizeT / sizeU) - 1)) );
        }

        template<typename U, std::enable_if_t<(sizeof(U) == sizeof(T))>* = nullptr>
        explicit Register(const U val, const u8 idx = 0) :
            value{ static_cast<T>( val ) }, bits{ value }
        {}

        template<typename... Args>
        Register(Args... args) {}

        template<typename U>
        Register(const Register<U>& reg, const u8 idx = 0) : Register(reg.value, idx) {}

        void changeEndian() {
            T tmp = value;
            char* const p = reinterpret_cast<char*>(&tmp);
            for (size_t i = 0; i < sizeof(T) / 2; ++i)
                std::swap(p[i], p[sizeof(T) - i - 1]);
            bits = tmp;
        }

        Register& operator=(const Register& obj) {
            this->value = obj.value;
            //this->previous_value = obj.previous_value;
            this->bits = obj.bits;
            return *this;
        }

        template<typename Lhs, typename Rhs>
        friend auto operator+(const Register<Lhs>& l, const Register<Rhs>& r);

        template<typename Lhs, typename Rhs>
        friend auto operator-(const Register<Lhs>& l, const Register<Rhs>& r);

        template<typename Lhs, typename Rhs>
        friend auto operator*(const Register<Lhs>& l, const Register<Rhs>& r);

        template<typename Lhs, typename Rhs>
        friend auto operator/(const Register<Lhs>& l, const Register<Rhs>& r);

        template<typename Lhs, typename Rhs>
        friend auto operator%(const Register<Lhs>& l, const Register<Rhs>& r);

        template<typename Lhs, typename Rhs>
        friend auto operator&(const Register<Lhs>& l, const Register<Rhs>& r);

        template<typename Lhs, typename Rhs>
        friend auto operator|(const Register<Lhs>& l, const Register<Rhs>& r);

        template<typename Lhs, typename Rhs>
        friend auto operator^(const Register<Lhs>& l, const Register<Rhs>& r);

        template<typename Reg>
        friend auto operator~(const Register<Reg>& l);
    };

    template<typename Lhs, typename Rhs>
    auto operator+(const Register<Lhs>& l, const Register<Rhs>& r) {    
        return Register<decltype(l.value + r.value)>{ l.value + r.value };
    }

    template<typename Lhs, typename Rhs>
    auto operator-(const Register<Lhs>& l, const Register<Rhs>& r) {
        return Register<decltype(l.value - r.value)>{ l.value - r.value };
    }

    template<typename Lhs, typename Rhs>
    auto operator*(const Register<Lhs>& l, const Register<Rhs>& r) {
        return Register<decltype(l.value * r.value)>{ l.value * r.value };
    }

    template<typename Lhs, typename Rhs>
    auto operator/(const Register<Lhs>& l, const Register<Rhs>& r) {
        if (r.value == 0)
            throw std::exception( "Division by 0\n" );
        return Register<decltype(l.value / r.value)>{ l.value / r.value };
    }

    template<typename Lhs, typename Rhs>
    auto operator%(const Register<Lhs>& l, const Register<Rhs>& r) {
        return Register<decltype(l.value % r.value)>{ l.value % r.value };
    }

    template<typename Lhs, typename Rhs>
    auto operator&(const Register<Lhs>& l, const Register<Rhs>& r) {
        return Register<decltype(l.value & r.value)>{ l.value & r.value};
    }

    template<typename Lhs, typename Rhs>
    auto operator|(const Register<Lhs>& l, const Register<Rhs>& r) {
        return Register<decltype(l.value | r.value)>{ l.value | r.value};
    }

    template<typename Lhs, typename Rhs>
    auto operator^(const Register<Lhs>& l, const Register<Rhs>& r) {
        return Register<decltype(l.value ^ r.value)>{ l.value ^ r.value };
    }

    template<typename Reg>
    auto operator~(const Register<Reg>& r) {
        return Register<decltype(~r.value)>{~r.value};
    }

    template<typename T>
    std::ostream& operator<<(std::ostream& os, const Register<T>& r) {
        return os << "Reg" << std::size(r.bits) << '(' << +r.value << ")"
            << "\nhex: 0x" << std::uppercase << std::setfill('0') << std::setw(sizeof(T) * 2) << std::hex
            << +r.bits.to_ullong() << std::dec << "\nbin: "
            << r.bits << "\n\n";
    }

    template<typename T>
    T changeEndian(T in) {
        char* const p = reinterpret_cast<char*>(&in);
        for (size_t i = 0; i < sizeof(T) / 2; ++i)
            std::swap(p[i], p[sizeof(T) - i - 1]);
        return in;
    }

    template<typename T>
    Register<T> reverseBitOrder(Register<T>& reg, bool copy = false) {
        static constexpr u16 BitCount = sizeof(T) * CHAR_BIT;

        auto str = reg.bits.to_string();
        std::reverse(str.begin(), str.end());

        if (copy) { // return a copy
            Register<T> cpy;
            cpy.bits = std::bitset<BitCount>(str);
            cpy.value = static_cast<T>(cpy.bits.to_ullong());
            return cpy;
        }
        else {
            reg.bits = std::bitset<BitCount>(str);
            //reg.previous_value = reg.value;
            reg.value = static_cast<T>(reg.bits.to_ullong());
            return {};
        }
    }    
} // namespace vpc

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Answer 1

您的错误与转换类型无关

if x > x_high，那么您永远不会为loss赋值，但是您正在检查if loss < max_loss，并且loss不存在

您应该在for循环之前为其分配一些默认值，就像您为最大损失所做的那样

此外，您有一个无限的while循环，因为len(stock_value) < number_of_stocks始终为true。股票的长度或数量改变价值

如何在python中解决此Nameerror

1 个答案: