Backslash '\' in value causes exception

[TQwan]

• What is the issue you have?

backslash '\' in field value of json file causes an exception.

• Please describe the steps to reproduce the issue. Can you provide a small but working code example?

#include <nlohmann/json.hpp>

using json = nlohmann::json;

#include <iostream>     // std::cout
#include <fstream>      // std::ifstream
#include <ostream>      // std::ofstream
#include <iomanip>
#include <string>

// Note: nlohmann '<<' operator currently doesn't work with VS2019, so read file manually.
std::ifstream i;
i.open("examplefile.json", std::ifstream::in);
std::string x = "";
char c = i.get();
while (i.good()) {
    x += c;
    c = i.get();
}
i.close();

// parse explicitly
auto j3 = json::parse(x.c_str());

examplefile.json

{
    "Models": [
        {
            "path": "thispath\NOTworking.dae",
            "X": 0,
            "Y": 0,
            "Z": 0
        },
        {
            "path": "other.dae",
            "X": 0,
            "Y": 0,
            "Z": 0
        }
    ]
}

Note that forward slash does work.
examplefile2.json

{
    "Models": [
        {
            "path": "thispath/working.dae",
            "X": 0,
            "Y": 0,
            "Z": 0
        },
        {
            "path": "other.dae",
            "X": 0,
            "Y": 0,
            "Z": 0
        }
    ]
}

• What is the expected behavior?
  File should just parse like the example2 (but with an string escaped backslash).

• And what is the actual behavior instead?
  Program crash due to thrown exception.

• Which compiler and operating system are you using? Is it a supported compiler?
  Microsoft Visual C++ 2019

• Did you use a released version of the library or the version from the develop branch?
  Tryed both 3.6.1 and 3.70

• If you experience a compilation error: can you compile and run the unit tests?
  No compilation error

[nlohmann]

Backslashes need to be escaped. I guess the exception is a parse error telling this.

[nlohmann]

What is the exact exception text?

[gregmarr]

[nlohmann]

One more question:

// Note: nlohmann '<<' operator currently doesn't work with VS2019, so read file manually.

Does code with << actually not compile or is it just a warning in the editor?

[ghost]

Does code with << actually not compile or is it just a warning in the editor?

For me, it compiles but generates a warning...

1>Z:\blah\console.cpp(38,1): warning C4996: 'nlohmann::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::adl_serializer>::operator <<': Since 3.0.0
1>Z:\blah\console.cpp(38,1): warning C4996: 	j << i;
1>Z:\blah\console.cpp(38,1): warning C4996: ^
1>Z:\blah\json.hpp(20730): message : see declaration of 'nlohmann::basic_json<std::map,std::vector,std::string,bool,int64_t,uint64_t,double,std::allocator,nlohmann::adl_serializer>::operator <<'
1>Z:\blah\json.hpp(20730): message :     friend std::istream& operator<<(basic_json& j, std::istream& i)

VS2019 16.3.7.

[nlohmann]

That's fine. The function is indeed deprecated.

[nlohmann]

Do you need further assistance with this issue?