ceph/src/jaegertracing/opentelemetry-cpp/third_party/nlohmann-json/doc/examples/basic_json__value_ptr.cpp

   1 #include <iostream>
   2 #include <nlohmann/json.hpp>
   3
   4 using json = nlohmann::json;
   5
   6 int main()
   7 {
   8     // create a JSON object with different entry types
   9     json j =
  10     {
  11         {"integer", 1},
  12         {"floating", 42.23},
  13         {"string", "hello world"},
  14         {"boolean", true},
  15         {"object", {{"key1", 1}, {"key2", 2}}},
  16         {"array", {1, 2, 3}}
  17     };
  18
  19     // access existing values
  20     int v_integer = j.value("/integer"_json_pointer, 0);
  21     double v_floating = j.value("/floating"_json_pointer, 47.11);
  22
  23     // access nonexisting values and rely on default value
  24     std::string v_string = j.value("/nonexisting"_json_pointer, "oops");
  25     bool v_boolean = j.value("/nonexisting"_json_pointer, false);
  26
  27     // output values
  28     std::cout << std::boolalpha << v_integer << " " << v_floating
  29               << " " << v_string << " " << v_boolean << "\n";
  30 }