json/doc/examples/emplace.cpp

32 lines
775 B
C++
Raw Normal View History

#include <iostream>
#include <nlohmann/json.hpp>
using json = nlohmann::json;
int main()
{
// create JSON values
json object = {{"one", 1}, {"two", 2}};
json null;
// print values
std::cout << object << '\n';
std::cout << null << '\n';
// add values
auto res1 = object.emplace("three", 3);
null.emplace("A", "a");
null.emplace("B", "b");
// the following call will not add an object, because there is already
// a value stored at key "B"
auto res2 = null.emplace("B", "c");
// print values
std::cout << object << '\n';
std::cout << *res1.first << " " << std::boolalpha << res1.second << '\n';
std::cout << null << '\n';
std::cout << *res2.first << " " << std::boolalpha << res2.second << '\n';
}