cleanup and documentation

doc/examples/flatten.cpp

+#include <json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // create JSON value
+    json j =
+    {
+        {"pi", 3.141},
+        {"happy", true},
+        {"name", "Niels"},
+        {"nothing", nullptr},
+        {
+            "answer", {
+                {"everything", 42}
+            }
+        },
+        {"list", {1, 0, 2}},
+        {
+            "object", {
+                {"currency", "USD"},
+                {"value", 42.99},
+                {"", "empty string"},
+                {"/", "slash"},
+                {"~", "tilde"},
+                {"~1", "tilde1"}
+            }
+        }
+    };
+
+    // call flatten()
+    std::cout << std::setw(4) << j.flatten() << '\n';
+}

doc/examples/flatten.link

+<a target="_blank" href="http://melpon.org/wandbox/permlink/kODXfzcksgstdBRD"><b>online</b></a>
\ No newline at end of file

doc/examples/flatten.output

+{
+    "/answer/everything": 42,
+    "/happy": true,
+    "/list/0": 1,
+    "/list/1": 0,
+    "/list/2": 2,
+    "/name": "Niels",
+    "/nothing": null,
+    "/object/": "empty string",
+    "/object/currency": "USD",
+    "/object/value": 42.99,
+    "/object/~0": "tilde",
+    "/object/~01": "tilde1",
+    "/object/~1": "slash",
+    "/pi": 3.141
+}

doc/examples/operatorjson_pointer.cpp

+#include <json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // create a JSON value
+    json j =
+    {
+        {"number", 1}, {"string", "foo"}, {"array", {1, 2}}
+    };
+
+    // read-only access
+
+    // output element with JSON pointer "/number"
+    std::cout << j["/number"_json_pointer] << '\n';
+    // output element with JSON pointer "/string"
+    std::cout << j["/string"_json_pointer] << '\n';
+    // output element with JSON pointer "/array"
+    std::cout << j["/array"_json_pointer] << '\n';
+    // output element with JSON pointer "/array/1"
+    std::cout << j["/array/1"_json_pointer] << '\n';
+
+    // writing access
+
+    // change the string
+    j["/string"_json_pointer] = "bar";
+    // output the changed string
+    std::cout << j["string"] << '\n';
+
+    // "change" a nonexisting object entry
+    j["/boolean"_json_pointer] = true;
+    // output the changed object
+    std::cout << j << '\n';
+
+    // change an array element
+    j["/array/1"_json_pointer] = 21;
+    // "change" an array element with nonexisting index
+    j["/array/4"_json_pointer] = 44;
+    // output the changed array
+    std::cout << j["array"] << '\n';
+
+    // "change" the arry element past the end
+    j["/array/-"_json_pointer] = 55;
+    // output the changed array
+    std::cout << j["array"] << '\n';
+}

doc/examples/operatorjson_pointer.link

+<a target="_blank" href="http://melpon.org/wandbox/permlink/6oeNnra3wjPijLSr"><b>online</b></a>
\ No newline at end of file

doc/examples/operatorjson_pointer.output

+1
+"foo"
+[1,2]
+2
+"bar"
+{"array":[1,2],"boolean":true,"number":1,"string":"bar"}
+[1,21,null,null,44]
+[1,21,null,null,44,55]

doc/examples/operatorjson_pointer_const.cpp

+#include <json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // create a JSON value
+    const json j =
+    {
+        {"number", 1}, {"string", "foo"}, {"array", {1, 2}}
+    };
+
+    // read-only access
+
+    // output element with JSON pointer "/number"
+    std::cout << j["/number"_json_pointer] << '\n';
+    // output element with JSON pointer "/string"
+    std::cout << j["/string"_json_pointer] << '\n';
+    // output element with JSON pointer "/array"
+    std::cout << j["/array"_json_pointer] << '\n';
+    // output element with JSON pointer "/array/1"
+    std::cout << j["/array/1"_json_pointer] << '\n';
+}

doc/examples/operatorjson_pointer_const.link

+<a target="_blank" href="http://melpon.org/wandbox/permlink/YmjwNAhsoeMXw5Ve"><b>online</b></a>
\ No newline at end of file

doc/examples/operatorjson_pointer_const.output

+1
+"foo"
+[1,2]
+2

doc/examples/unflatten.cpp

+#include <json.hpp>
+
+using json = nlohmann::json;
+
+int main()
+{
+    // create JSON value
+    json j_flattened =
+    {
+        {"/answer/everything", 42},
+        {"/happy", true},
+        {"/list/0", 1},
+        {"/list/1", 0},
+        {"/list/2", 2},
+        {"/name", "Niels"},
+        {"/nothing", nullptr},
+        {"/object/", "empty string"},
+        {"/object/currency", "USD"},
+        {"/object/value", 42.99},
+        {"/object/~0", "tilde"},
+        {"/object/~01", "tilde1"},
+        {"/object/~1", "slash"},
+        {"/pi", 3.141}
+    };
+
+    // call unflatten()
+    std::cout << std::setw(4) << j_flattened.unflatten() << '\n';
+}

doc/examples/unflatten.link

+<a target="_blank" href="http://melpon.org/wandbox/permlink/ITqCZsXmi0I7KGYy"><b>online</b></a>
\ No newline at end of file

doc/examples/unflatten.output

+{
+    "answer": {
+        "everything": 42
+    },
+    "happy": true,
+    "list": [
+        1,
+        0,
+        2
+    ],
+    "name": "Niels",
+    "nothing": null,
+    "object": {
+        "": "empty string",
+        "/": "slash",
+        "currency": "USD",
+        "value": 42.99,
+        "~": "tilde",
+        "~1": "tilde1"
+    },
+    "pi": 3.141
+}