Merge pull request Tencent#1421 from HomeControlAS/sort_by_name_example

added example for sorting keys

Author: miloyip

example/CMakeLists.txt

@@ -21,6 +21,7 @@ set(EXAMPLES
     simplereader
     simplepullreader
     simplewriter
+    sortkeys
     tutorial)
 
 include_directories("../include/")

example/sortkeys/sortkeys.cpp

@@ -0,0 +1,66 @@
+#include "rapidjson/document.h"
+#include "rapidjson/filewritestream.h"
+#include <rapidjson/prettywriter.h>
+
+#include <algorithm>
+#include <iostream>
+
+using namespace rapidjson;
+using namespace std;
+
+void printIt(const Value &doc)
+{
+    char writeBuffer[65536];
+    FileWriteStream os(stdout, writeBuffer, sizeof(writeBuffer));
+    PrettyWriter<FileWriteStream> writer(os);
+    doc.Accept(writer);
+
+    cout << endl;
+}
+
+struct NameComparator
+{
+    bool
+    operator()(const GenericMember<UTF8<>, MemoryPoolAllocator<>> &lhs,
+               const GenericMember<UTF8<>, MemoryPoolAllocator<>> &rhs) const
+    {
+        return (strcmp(lhs.name.GetString(), rhs.name.GetString()) < 0);
+    }
+};
+
+int main()
+{
+    Document d = Document(kObjectType);
+    Document::AllocatorType &allocator = d.GetAllocator();
+
+    d.AddMember("zeta", Value().SetBool(false), allocator);
+    d.AddMember("gama", Value().SetString("test string", allocator), allocator);
+    d.AddMember("delta", Value().SetInt(123), allocator);
+
+    Value a(kArrayType);
+    d.AddMember("alpha", a, allocator);
+
+    printIt(d);
+
+    /**
+{
+    "zeta": false,
+    "gama": "test string",
+    "delta": 123,
+    "alpha": []
+}
+**/
+
+    std::sort(d.MemberBegin(), d.MemberEnd(), NameComparator());
+
+    printIt(d);
+    /**
+{
+  "alpha": [],
+  "delta": 123,
+  "gama": "test string",
+  "zeta": false
+}
+**/
+    return 0;
+}