nlohmannjson/doc/examples/json_pointer__push_back.cpp

#include <iostream>
#include <nlohmann/json.hpp>

using json = nlohmann::json;

int main()
{
    // create empty JSON Pointer
    json::json_pointer ptr;
    std::cout << ptr << '\n';

    // call push_back()
    ptr.push_back("foo");
    std::cout << ptr << '\n';

    ptr.push_back("0");
    std::cout << ptr << '\n';

    ptr.push_back("bar");
    std::cout << ptr << '\n';
}