Initial import of libdpf.

Co-authored-by: Cursor <cursoragent@cursor.com>

thirdparty/json/docs/examples/operator__notequal__nullptr_t.cpp

@@ -0,0 +1,22 @@
+#include <iostream>
+#include <nlohmann/json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // create several JSON values
+    json array = {1, 2, 3};
+    json object = {{"A", "a"}, {"B", "b"}};
+    json number = 17;
+    json string = "foo";
+    json null;
+
+    // output values and comparisons
+    std::cout << std::boolalpha;
+    std::cout << array << " != nullptr " << (array != nullptr) << '\n';
+    std::cout << object << " != nullptr " << (object != nullptr) << '\n';
+    std::cout << number << " != nullptr " << (number != nullptr) << '\n';
+    std::cout << string << " != nullptr " << (string != nullptr) << '\n';
+    std::cout << null << " != nullptr " << (null != nullptr) << '\n';
+}