doc/examples/json_pointer__parent_pointer.cpp

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

using json = nlohmann::json;

int main()
{
    // different JSON Pointers
    json::json_pointer ptr1("");
    json::json_pointer ptr2("/foo");
    json::json_pointer ptr3("/foo/0");

    // call parent_pointer()
    std::cout << std::boolalpha
              << "parent of " << ptr1 << " is " << ptr1.parent_pointer() << '\n'
              << "parent of " << ptr2 << " is " << ptr2.parent_pointer() << '\n'
              << "parent of " << ptr3 << " is " << ptr3.parent_pointer() << std::endl;
}