Merge commit 'b9112977b074d67d6c83f04af36b6dabdf1d92c6' as 'external/json'

external/json/docs/examples/empty.cpp

@@ -0,0 +1,30 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // create JSON values
+    json j_null;
+    json j_boolean = true;
+    json j_number_integer = 17;
+    json j_number_float = 23.42;
+    json j_object = {{"one", 1}, {"two", 2}};
+    json j_object_empty(json::value_t::object);
+    json j_array = {1, 2, 4, 8, 16};
+    json j_array_empty(json::value_t::array);
+    json j_string = "Hello, world";
+
+    // call empty()
+    std::cout << std::boolalpha;
+    std::cout << j_null.empty() << '\n';
+    std::cout << j_boolean.empty() << '\n';
+    std::cout << j_number_integer.empty() << '\n';
+    std::cout << j_number_float.empty() << '\n';
+    std::cout << j_object.empty() << '\n';
+    std::cout << j_object_empty.empty() << '\n';
+    std::cout << j_array.empty() << '\n';
+    std::cout << j_array_empty.empty() << '\n';
+    std::cout << j_string.empty() << '\n';
+}