使用nlohmann json创建的json解析后如何获取数据

Question

我需要以下列格式在 Json 中存储两个结构，即一和二，然后解析此 JSON 并将数据存储回那些结构对象。

{ "One",{
            { "Value1", one.Value1() },
        }
        },
{ "Two",{
            { "Value1", two.Value1() },
            { "Value2", two.Value2() }
        }
        },

我能够将数据存储在 json 文件中，但是当我读回它以获取结构值时，出现以下错误：

1>c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\consoleapplication6.cpp(72): error C3867: 'One::Value1': non-standard syntax; use '&' to create a pointer to member
1>c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\consoleapplication6.cpp(72): error C2672: 'nlohmann::json_abi_v3_11_2::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::json_abi_v3_11_2::adl_serializer,std::vector<uint8_t,std::allocator<_Ty>>>::get_to': no matching overloaded function found
1>          with
1>          [
1>              _Ty=uint8_t
1>          ]
1>c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\consoleapplication6.cpp(87): error C2672: 'nlohmann::json_abi_v3_11_2::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::json_abi_v3_11_2::adl_serializer,std::vector<uint8_t,std::allocator<_Ty>>>::get': no matching overloaded function found
1>          with
1>          [
1>              _Ty=uint8_t
1>          ]
1>c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\consoleapplication6.cpp(87): error C2783: 'unknown-type nlohmann::json_abi_v3_11_2::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::json_abi_v3_11_2::adl_serializer,std::vector<uint8_t,std::allocator<_Ty>>>::get(void) noexcept': could not deduce template argument for '__formal'
1>          with
1>          [
1>              _Ty=uint8_t
1>          ]
1>  c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\nlohmann\json.hpp(20950): note: see declaration of 'nlohmann::json_abi_v3_11_2::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::json_abi_v3_11_2::adl_serializer,std::vector<uint8_t,std::allocator<_Ty>>>::get'
1>          with
1>          [
1>              _Ty=uint8_t
1>          ]
1>c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\consoleapplication6.cpp(87): error C2893: Failed to specialize function template 'unknown-type nlohmann::json_abi_v3_11_2::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::json_abi_v3_11_2::adl_serializer,std::vector<uint8_t,std::allocator<_Ty>>>::get(void) noexcept(<expr>) const'
1>          with
1>          [
1>              _Ty=uint8_t
1>          ]
1>  c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\consoleapplication6.cpp(87): note: With the following template arguments:
1>  c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\consoleapplication6.cpp(87): note: 'ValueTypeCV=One'
1>  c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\consoleapplication6.cpp(87): note: 'ValueType=One'
1>c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\consoleapplication6.cpp(87): error C2512: 'One': no appropriate default constructor available
1>  c:\users\212506\documents\visual studio 2015\projects\consoleapplication6\consoleapplication6\consoleapplication6.cpp(35): note: see declaration of 'One'

我正在工作的代码是：

// ConsoleApplication5.cpp : Defines the entry point for the console application.

#include "stdafx.h"
#include <iostream>
#include <string>
#include <array>
#include <initializer_list>

#include "nlohmann/json.hpp"
using nlohmann::json;

class Two
{
public:
    Two(int val1, int val2) :
        m_Value1(val1), m_Value2(val2)
    {
    }

    int Value1()
    {
        return m_Value1;
    }
    int Value2()
    {
        return m_Value2;
    }

public:
    int m_Value1;
    int m_Value2;
};

class One
{
public:
    One(int val1) :
        m_Value1_1(val1)
    {
    }
    int Value1()
    {
        return m_Value1_1;
    }

public:
    int m_Value1_1;
};

std::string ToJsonString(One &one, Two &two)
{
    nlohmann::json j =
    {
        { "One",{
            { "Value1", one.Value1() },
        }
        },
        { "Two",{
            { "Value1", two.Value1() },
            { "Value2", two.Value2() }
        }
        },
    };

    std::cout << j.dump(4) << std::endl;
    std::string str = j.dump(4);
    return str;
}

void from_json(const json& j, One& one)
{
    j.at("Value1").get_to(one.Value1);
}

void ToObjectsOne(std::string json)
{
    nlohmann::json data;
    try
    {
        data = nlohmann::json::parse(json);
    }
    catch (nlohmann::json::exception& exception)
    {
        std::cerr << "Exception[" << exception.what() << "]";
    }

    One one = data["One"].get<One>();
}


int main()
{
    One one(10);
    Two two(10, 20);

    std::string jsonStr = ToJsonString(one, two);

    ToObjectsOne(jsonStr);

    return 0;
}

请让我知道我们是否可以使用这种方式：

One one = data["One"].get<One>();

如果不是那么我应该如何从两个结构的 json 中获取值。