Deserializing to a struct as shown on the project homepage throws compile time errors

[kitattyor]

Can you provide a small but working code example?

Code:

static void throwaway2() {
  // a simple struct to model a person
  struct person {
    std::string name;
    std::string address;
    int age;
  };
  // create a person
  person p{"Ned Flanders", "744 Evergreen Terrace", 60};

  // conversion: person -> json
  auto j = R"({
	"name": "Ned Flanders",
	"address": "744 Evergreen Terrace",
	"age": 60
		})"_json;

  std::cout << j << std::endl;

  auto p2 = j.get<person>(); // Error here 

  assert(p == p2);
}

Error:

error C2672: 'nlohmann::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::adl_serializer,std::vector<uint8_t,std::allocator<uint8_t>>>::get': no matching overloaded function found 

error C2783: 'nlohmann::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::adl_serializer,std::vector<uint8_t,std::allocator<uint8_t>>> nlohmann::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::adl_serializer,std::vector<uint8_t,std::allocator<uint8_t>>>::get(void) const': could not deduce template argument for '__formal' 

[build] D:\Libs\vcpkg\installed\x64-windows\include\nlohmann/json.hpp(2848): message : see declaration of 'nlohmann::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::adl_serializer,std::vector<uint8_t,std::allocator<uint8_t>>>::get' 

• Compiler: ___ Visual Studio 2017 x64
• Operating system: ___ Windows 10

Which version of the library did you use?

• latest release version 3.9.1
• other release - please state the version: ___
• the develop branch

[nlohmann]

It's described here: https://github.com/nlohmann/json#basic-usage:

To make this work with one of your types, you only need to provide two functions:

using nlohmann::json;

namespace ns {
    void to_json(json& j, const person& p) {
        j = json{{"name", p.name}, {"address", p.address}, {"age", p.age}};
    }

    void from_json(const json& j, person& p) {
        j.at("name").get_to(p.name);
        j.at("address").get_to(p.address);
        j.at("age").get_to(p.age);
    }
} // namespace ns

[kitattyor]

Thanks, it works now.. Should have kept reading to the next section.. closing.. 😅

…

On Fri, Mar 5, 2021 at 9:30 PM Niels Lohmann ***@***.***> wrote: It's described here: https://github.com/nlohmann/json#basic-usage: To make this work with one of your types, you only need to provide two functions: using nlohmann::json; namespace ns { void to_json(json& j, const person& p) { j = json{{"name", p.name}, {"address", p.address}, {"age", p.age}}; } void from_json(const json& j, person& p) { j.at("name").get_to(p.name); j.at("address").get_to(p.address); j.at("age").get_to(p.age); } } // namespace ns — You are receiving this because you authored the thread. Reply to this email directly, view it on GitHub <#2665 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AKZZXQIROFZYYCMOCBBTZKTTCDMFRANCNFSM4YUMQMQQ> .