Support binary search for struct in cpp (#4245)

* Support binary search for struct in cpp

CreateVectorOfSortedStruct is provided for convenience.

* fix continuous-integration error

* add generated files

* compile Ability.cs in csharp test

* compile Ability.cs in csharp

* modify according to code review

include/flatbuffers/flatbuffers.h

@@ -1204,6 +1204,44 @@ FLATBUFFERS_FINAL_CLASS
     return CreateVectorOfStructs(data(v), v.size());
   }
 
+  /// @cond FLATBUFFERS_INTERNAL
+  template<typename T>
+  struct StructKeyComparator {
+    bool operator()(const T &a, const T &b) const {
+      return a.KeyCompareLessThan(&b);
+    }
+
+  private:
+    StructKeyComparator& operator= (const StructKeyComparator&);
+  };
+  /// @endcond
+
+  /// @brief Serialize a `std::vector` of structs into a FlatBuffer `vector`
+  /// in sorted order.
+  /// @tparam T The data type of the `std::vector` struct elements.
+  /// @param[in]] v A const reference to the `std::vector` of structs to
+  /// serialize into the buffer as a `vector`.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T> Offset<Vector<const T *>> CreateVectorOfSortedStructs(
+      std::vector<T> *v) {
+    return CreateVectorOfSortedStructs(data(*v), v->size());
+  }
+
+  /// @brief Serialize an array of structs into a FlatBuffer `vector` in sorted
+  /// order.
+  /// @tparam T The data type of the struct array elements.
+  /// @param[in] v A pointer to the array of type `T` to serialize into the
+  /// buffer as a `vector`.
+  /// @param[in] len The number of elements to serialize.
+  /// @return Returns a typed `Offset` into the serialized data indicating
+  /// where the vector is stored.
+  template<typename T> Offset<Vector<const T *>> CreateVectorOfSortedStructs(
+      T *v, size_t len) {
+    std::sort(v, v + len, StructKeyComparator<T>());
+    return CreateVectorOfStructs(v, len);
+  }
+
   /// @cond FLATBUFFERS_INTERNAL
   template<typename T>
   struct TableKeyComparator {

src/idl_gen_cpp.cpp

@@ -1943,6 +1943,24 @@ class CppGenerator : public BaseGenerator {
           code_ += "  }";
         }
       }
+
+      // Generate a comparison function for this field if it is a key.
+      if (field.key) {
+        code_ += "  bool KeyCompareLessThan(const {{STRUCT_NAME}} *o) const {";
+        code_ += "    return {{FIELD_NAME}}() < o->{{FIELD_NAME}}();";
+        code_ += "  }";
+        auto type = GenTypeBasic(field.value.type, false);
+        if (parser_.opts.scoped_enums && field.value.type.enum_def &&
+            IsScalar(field.value.type.base_type)) {
+          type = GenTypeGet(field.value.type, " ", "const ", " *", true);
+        }
+
+        code_.SetValue("KEY_TYPE", type);
+        code_ += "  int KeyCompareWithValue({{KEY_TYPE}} val) const {";
+        code_ += "    const auto key = {{FIELD_NAME}}();";
+        code_ += "    return static_cast<int>(key > val) - static_cast<int>(key < val);";
+        code_ += "  }";
+      }
     }
     code_ += "};";
 

src/idl_gen_general.cpp

@@ -1291,7 +1291,9 @@ void GenStruct(StructDef &struct_def, std::string *code_ptr) {
       code += "); }\n";
     }
   }
-  if (struct_def.has_key) {
+  // Only generate key compare function for table,
+  // because `key_field` is not set for struct
+  if (struct_def.has_key && !struct_def.fixed) {
     if (lang_.language == IDLOptions::kJava) {
       code += "\n  @Override\n  protected int keysCompare(";
       code += "Integer o1, Integer o2, ByteBuffer _bb) {";

tests/FlatBuffers.Test/FlatBuffers.Test.csproj

@@ -80,6 +80,9 @@
     <Compile Include="..\MyGame\Example\Vec3.cs">
       <Link>MyGame\Example\Vec3.cs</Link>
     </Compile>
+    <Compile Include="..\MyGame\Example\Ability.cs">
+      <Link>MyGame\Example\Ability.cs</Link>
+    </Compile>
     <Compile Include="..\namespace_test\NamespaceA\NamespaceB\EnumInNestedNS.cs">
       <Link>NamespaceA\NamespaceB\EnumInNestedNS.cs</Link>
     </Compile>

tests/MyGame/Example/Ability.cs

@@ -0,0 +1,30 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+namespace MyGame.Example
+{
+
+using System;
+using FlatBuffers;
+
+public struct Ability : IFlatbufferObject
+{
+  private Struct __p;
+  public ByteBuffer ByteBuffer { get { return __p.bb; } }
+  public void __init(int _i, ByteBuffer _bb) { __p.bb_pos = _i; __p.bb = _bb; }
+  public Ability __assign(int _i, ByteBuffer _bb) { __init(_i, _bb); return this; }
+
+  public uint Id { get { return __p.bb.GetUint(__p.bb_pos + 0); } }
+  public void MutateId(uint id) { __p.bb.PutUint(__p.bb_pos + 0, id); }
+  public uint Distance { get { return __p.bb.GetUint(__p.bb_pos + 4); } }
+  public void MutateDistance(uint distance) { __p.bb.PutUint(__p.bb_pos + 4, distance); }
+
+  public static Offset<Ability> CreateAbility(FlatBufferBuilder builder, uint Id, uint Distance) {
+    builder.Prep(4, 8);
+    builder.PutUint(Distance);
+    builder.PutUint(Id);
+    return new Offset<Ability>(builder.Offset);
+  }
+};
+
+
+}

tests/MyGame/Example/Ability.go

@@ -0,0 +1,41 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+package Example
+
+import (
+	flatbuffers "github.com/google/flatbuffers/go"
+)
+
+type Ability struct {
+	_tab flatbuffers.Struct
+}
+
+func (rcv *Ability) Init(buf []byte, i flatbuffers.UOffsetT) {
+	rcv._tab.Bytes = buf
+	rcv._tab.Pos = i
+}
+
+func (rcv *Ability) Table() flatbuffers.Table {
+	return rcv._tab.Table
+}
+
+func (rcv *Ability) Id() uint32 {
+	return rcv._tab.GetUint32(rcv._tab.Pos + flatbuffers.UOffsetT(0))
+}
+func (rcv *Ability) MutateId(n uint32) bool {
+	return rcv._tab.MutateUint32(rcv._tab.Pos+flatbuffers.UOffsetT(0), n)
+}
+
+func (rcv *Ability) Distance() uint32 {
+	return rcv._tab.GetUint32(rcv._tab.Pos + flatbuffers.UOffsetT(4))
+}
+func (rcv *Ability) MutateDistance(n uint32) bool {
+	return rcv._tab.MutateUint32(rcv._tab.Pos+flatbuffers.UOffsetT(4), n)
+}
+
+func CreateAbility(builder *flatbuffers.Builder, id uint32, distance uint32) flatbuffers.UOffsetT {
+	builder.Prep(4, 8)
+	builder.PrependUint32(distance)
+	builder.PrependUint32(id)
+	return builder.Offset()
+}

tests/MyGame/Example/Ability.java

@@ -0,0 +1,27 @@
+// automatically generated by the FlatBuffers compiler, do not modify
+
+package MyGame.Example;
+
+import java.nio.*;
+import java.lang.*;
+import java.util.*;
+import com.google.flatbuffers.*;
+
+@SuppressWarnings("unused")
+public final class Ability extends Struct {
+  public void __init(int _i, ByteBuffer _bb) { bb_pos = _i; bb = _bb; }
+  public Ability __assign(int _i, ByteBuffer _bb) { __init(_i, _bb); return this; }
+
+  public long id() { return (long)bb.getInt(bb_pos + 0) & 0xFFFFFFFFL; }
+  public void mutateId(long id) { bb.putInt(bb_pos + 0, (int)id); }
+  public long distance() { return (long)bb.getInt(bb_pos + 4) & 0xFFFFFFFFL; }
+  public void mutateDistance(long distance) { bb.putInt(bb_pos + 4, (int)distance); }
+
+  public static int createAbility(FlatBufferBuilder builder, long id, long distance) {
+    builder.prep(4, 8);
+    builder.putInt((int)distance);
+    builder.putInt((int)id);
+    return builder.offset();
+  }
+}
+

tests/MyGame/Example/Ability.php

@@ -0,0 +1,52 @@
+<?php
+// automatically generated by the FlatBuffers compiler, do not modify
+
+namespace MyGame\Example;
+
+use \Google\FlatBuffers\Struct;
+use \Google\FlatBuffers\Table;
+use \Google\FlatBuffers\ByteBuffer;
+use \Google\FlatBuffers\FlatBufferBuilder;
+
+class Ability extends Struct
+{
+    /**
+     * @param int $_i offset
+     * @param ByteBuffer $_bb
+     * @return Ability
+     **/
+    public function init($_i, ByteBuffer $_bb)
+    {
+        $this->bb_pos = $_i;
+        $this->bb = $_bb;
+        return $this;
+    }
+
+    /**
+     * @return uint
+     */
+    public function GetId()
+    {
+        return $this->bb->getUint($this->bb_pos + 0);
+    }
+
+    /**
+     * @return uint
+     */
+    public function GetDistance()
+    {
+        return $this->bb->getUint($this->bb_pos + 4);
+    }
+
+
+    /**
+     * @return int offset
+     */
+    public static function createAbility(FlatBufferBuilder $builder, $id, $distance)
+    {
+        $builder->prep(4, 8);
+        $builder->putUint($distance);
+        $builder->putUint($id);
+        return $builder->offset();
+    }
+}

tests/MyGame/Example/Ability.py

@@ -0,0 +1,23 @@
+# automatically generated by the FlatBuffers compiler, do not modify
+
+# namespace: Example
+
+import flatbuffers
+
+class Ability(object):
+    __slots__ = ['_tab']
+
+    # Ability
+    def Init(self, buf, pos):
+        self._tab = flatbuffers.table.Table(buf, pos)
+
+    # Ability
+    def Id(self): return self._tab.Get(flatbuffers.number_types.Uint32Flags, self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(0))
+    # Ability
+    def Distance(self): return self._tab.Get(flatbuffers.number_types.Uint32Flags, self._tab.Pos + flatbuffers.number_types.UOffsetTFlags.py_type(4))
+
+def CreateAbility(builder, id, distance):
+    builder.Prep(4, 8)
+    builder.PrependUint32(distance)
+    builder.PrependUint32(id)
+    return builder.Offset()

tests/MyGame/Example/Monster.cs

@@ -78,8 +78,10 @@ public struct Monster : IFlatbufferObject
   public bool MutateTestf3(float testf3) { int o = __p.__offset(58); if (o != 0) { __p.bb.PutFloat(o + __p.bb_pos, testf3); return true; } else { return false; } }
   public string Testarrayofstring2(int j) { int o = __p.__offset(60); return o != 0 ? __p.__string(__p.__vector(o) + j * 4) : null; }
   public int Testarrayofstring2Length { get { int o = __p.__offset(60); return o != 0 ? __p.__vector_len(o) : 0; } }
+  public Ability? Testarrayofsortedstruct(int j) { int o = __p.__offset(62); return o != 0 ? (Ability?)(new Ability()).__assign(__p.__vector(o) + j * 8, __p.bb) : null; }
+  public int TestarrayofsortedstructLength { get { int o = __p.__offset(62); return o != 0 ? __p.__vector_len(o) : 0; } }
 
-  public static void StartMonster(FlatBufferBuilder builder) { builder.StartObject(29); }
+  public static void StartMonster(FlatBufferBuilder builder) { builder.StartObject(30); }
   public static void AddPos(FlatBufferBuilder builder, Offset<Vec3> posOffset) { builder.AddStruct(0, posOffset.Value, 0); }
   public static void AddMana(FlatBufferBuilder builder, short mana) { builder.AddShort(1, mana, 150); }
   public static void AddHp(FlatBufferBuilder builder, short hp) { builder.AddShort(2, hp, 100); }
@@ -121,6 +123,8 @@ public struct Monster : IFlatbufferObject
   public static void AddTestarrayofstring2(FlatBufferBuilder builder, VectorOffset testarrayofstring2Offset) { builder.AddOffset(28, testarrayofstring2Offset.Value, 0); }
   public static VectorOffset CreateTestarrayofstring2Vector(FlatBufferBuilder builder, StringOffset[] data) { builder.StartVector(4, data.Length, 4); for (int i = data.Length - 1; i >= 0; i--) builder.AddOffset(data[i].Value); return builder.EndVector(); }
   public static void StartTestarrayofstring2Vector(FlatBufferBuilder builder, int numElems) { builder.StartVector(4, numElems, 4); }
+  public static void AddTestarrayofsortedstruct(FlatBufferBuilder builder, VectorOffset testarrayofsortedstructOffset) { builder.AddOffset(29, testarrayofsortedstructOffset.Value, 0); }
+  public static void StartTestarrayofsortedstructVector(FlatBufferBuilder builder, int numElems) { builder.StartVector(8, numElems, 4); }
   public static Offset<Monster> EndMonster(FlatBufferBuilder builder) {
     int o = builder.EndObject();
     builder.Required(o, 10);  // name

tests/MyGame/Example/Monster.go

@@ -419,8 +419,27 @@ func (rcv *Monster) Testarrayofstring2Length() int {
 	return 0
 }
 
+func (rcv *Monster) Testarrayofsortedstruct(obj *Ability, j int) bool {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(62))
+	if o != 0 {
+		x := rcv._tab.Vector(o)
+		x += flatbuffers.UOffsetT(j) * 8
+		obj.Init(rcv._tab.Bytes, x)
+		return true
+	}
+	return false
+}
+
+func (rcv *Monster) TestarrayofsortedstructLength() int {
+	o := flatbuffers.UOffsetT(rcv._tab.Offset(62))
+	if o != 0 {
+		return rcv._tab.VectorLen(o)
+	}
+	return 0
+}
+
 func MonsterStart(builder *flatbuffers.Builder) {
-	builder.StartObject(29)
+	builder.StartObject(30)
 }
 func MonsterAddPos(builder *flatbuffers.Builder, pos flatbuffers.UOffsetT) {
 	builder.PrependStructSlot(0, flatbuffers.UOffsetT(pos), 0)
@@ -527,6 +546,12 @@ func MonsterAddTestarrayofstring2(builder *flatbuffers.Builder, testarrayofstrin
 func MonsterStartTestarrayofstring2Vector(builder *flatbuffers.Builder, numElems int) flatbuffers.UOffsetT {
 	return builder.StartVector(4, numElems, 4)
 }
+func MonsterAddTestarrayofsortedstruct(builder *flatbuffers.Builder, testarrayofsortedstruct flatbuffers.UOffsetT) {
+	builder.PrependUOffsetTSlot(29, flatbuffers.UOffsetT(testarrayofsortedstruct), 0)
+}
+func MonsterStartTestarrayofsortedstructVector(builder *flatbuffers.Builder, numElems int) flatbuffers.UOffsetT {
+	return builder.StartVector(8, numElems, 4)
+}
 func MonsterEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT {
 	return builder.EndObject()
 }

tests/MyGame/Example/Monster.java

@@ -87,8 +87,11 @@ public final class Monster extends Table {
   public boolean mutateTestf3(float testf3) { int o = __offset(58); if (o != 0) { bb.putFloat(o + bb_pos, testf3); return true; } else { return false; } }
   public String testarrayofstring2(int j) { int o = __offset(60); return o != 0 ? __string(__vector(o) + j * 4) : null; }
   public int testarrayofstring2Length() { int o = __offset(60); return o != 0 ? __vector_len(o) : 0; }
+  public Ability testarrayofsortedstruct(int j) { return testarrayofsortedstruct(new Ability(), j); }
+  public Ability testarrayofsortedstruct(Ability obj, int j) { int o = __offset(62); return o != 0 ? obj.__assign(__vector(o) + j * 8, bb) : null; }
+  public int testarrayofsortedstructLength() { int o = __offset(62); return o != 0 ? __vector_len(o) : 0; }
 
-  public static void startMonster(FlatBufferBuilder builder) { builder.startObject(29); }
+  public static void startMonster(FlatBufferBuilder builder) { builder.startObject(30); }
   public static void addPos(FlatBufferBuilder builder, int posOffset) { builder.addStruct(0, posOffset, 0); }
   public static void addMana(FlatBufferBuilder builder, short mana) { builder.addShort(1, mana, 150); }
   public static void addHp(FlatBufferBuilder builder, short hp) { builder.addShort(2, hp, 100); }
@@ -130,6 +133,8 @@ public final class Monster extends Table {
   public static void addTestarrayofstring2(FlatBufferBuilder builder, int testarrayofstring2Offset) { builder.addOffset(28, testarrayofstring2Offset, 0); }
   public static int createTestarrayofstring2Vector(FlatBufferBuilder builder, int[] data) { builder.startVector(4, data.length, 4); for (int i = data.length - 1; i >= 0; i--) builder.addOffset(data[i]); return builder.endVector(); }
   public static void startTestarrayofstring2Vector(FlatBufferBuilder builder, int numElems) { builder.startVector(4, numElems, 4); }
+  public static void addTestarrayofsortedstruct(FlatBufferBuilder builder, int testarrayofsortedstructOffset) { builder.addOffset(29, testarrayofsortedstructOffset, 0); }
+  public static void startTestarrayofsortedstructVector(FlatBufferBuilder builder, int numElems) { builder.startVector(8, numElems, 4); }
   public static int endMonster(FlatBufferBuilder builder) {
     int o = builder.endObject();
     builder.required(o, 10);  // name

tests/MyGame/Example/Monster.php

@@ -379,22 +379,41 @@ class Monster extends Table
         return $o != 0 ? $this->__vector_len($o) : 0;
     }
 
+    /**
+     * @returnVectorOffset
+     */
+    public function getTestarrayofsortedstruct($j)
+    {
+        $o = $this->__offset(62);
+        $obj = new Ability();
+        return $o != 0 ? $obj->init($this->__vector($o) + $j *8, $this->bb) : null;
+    }
+
+    /**
+     * @return int
+     */
+    public function getTestarrayofsortedstructLength()
+    {
+        $o = $this->__offset(62);
+        return $o != 0 ? $this->__vector_len($o) : 0;
+    }
+
     /**
      * @param FlatBufferBuilder $builder
      * @return void
      */
     public static function startMonster(FlatBufferBuilder $builder)
     {
-        $builder->StartObject(29);
+        $builder->StartObject(30);
     }
 
     /**
      * @param FlatBufferBuilder $builder
      * @return Monster
      */
-    public static function createMonster(FlatBufferBuilder $builder, $pos, $mana, $hp, $name, $inventory, $color, $test_type, $test, $test4, $testarrayofstring, $testarrayoftables, $enemy, $testnestedflatbuffer, $testempty, $testbool, $testhashs32_fnv1, $testhashu32_fnv1, $testhashs64_fnv1, $testhashu64_fnv1, $testhashs32_fnv1a, $testhashu32_fnv1a, $testhashs64_fnv1a, $testhashu64_fnv1a, $testarrayofbools, $testf, $testf2, $testf3, $testarrayofstring2)
+    public static function createMonster(FlatBufferBuilder $builder, $pos, $mana, $hp, $name, $inventory, $color, $test_type, $test, $test4, $testarrayofstring, $testarrayoftables, $enemy, $testnestedflatbuffer, $testempty, $testbool, $testhashs32_fnv1, $testhashu32_fnv1, $testhashs64_fnv1, $testhashu64_fnv1, $testhashs32_fnv1a, $testhashu32_fnv1a, $testhashs64_fnv1a, $testhashu64_fnv1a, $testarrayofbools, $testf, $testf2, $testf3, $testarrayofstring2, $testarrayofsortedstruct)
     {
-        $builder->startObject(29);
+        $builder->startObject(30);
         self::addPos($builder, $pos);
         self::addMana($builder, $mana);
         self::addHp($builder, $hp);
@@ -423,6 +442,7 @@ class Monster extends Table
         self::addTestf2($builder, $testf2);
         self::addTestf3($builder, $testf3);
         self::addTestarrayofstring2($builder, $testarrayofstring2);
+        self::addTestarrayofsortedstruct($builder, $testarrayofsortedstruct);
         $o = $builder->endObject();
         $builder->required($o, 10);  // name
         return $o;
@@ -871,6 +891,40 @@ class Monster extends Table
         $builder->startVector(4, $numElems, 4);
     }
 
+    /**
+     * @param FlatBufferBuilder $builder
+     * @param VectorOffset
+     * @return void
+     */
+    public static function addTestarrayofsortedstruct(FlatBufferBuilder $builder, $testarrayofsortedstruct)
+    {
+        $builder->addOffsetX(29, $testarrayofsortedstruct, 0);
+    }
+
+    /**
+     * @param FlatBufferBuilder $builder
+     * @param array offset array
+     * @return int vector offset
+     */
+    public static function createTestarrayofsortedstructVector(FlatBufferBuilder $builder, array $data)
+    {
+        $builder->startVector(8, count($data), 4);
+        for ($i = count($data) - 1; $i >= 0; $i--) {
+            $builder->addOffset($data[$i]);
+        }
+        return $builder->endVector();
+    }
+
+    /**
+     * @param FlatBufferBuilder $builder
+     * @param int $numElems
+     * @return void
+     */
+    public static function startTestarrayofsortedstructVector(FlatBufferBuilder $builder, $numElems)
+    {
+        $builder->startVector(8, $numElems, 4);
+    }
+
     /**
      * @param FlatBufferBuilder $builder
      * @return int table offset

tests/MyGame/Example/Monster.py

@@ -297,7 +297,26 @@ class Monster(object):
             return self._tab.VectorLen(o)
         return 0
 
-def MonsterStart(builder): builder.StartObject(29)
+    # Monster
+    def Testarrayofsortedstruct(self, j):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(62))
+        if o != 0:
+            x = self._tab.Vector(o)
+            x += flatbuffers.number_types.UOffsetTFlags.py_type(j) * 8
+            from .Ability import Ability
+            obj = Ability()
+            obj.Init(self._tab.Bytes, x)
+            return obj
+        return None
+
+    # Monster
+    def TestarrayofsortedstructLength(self):
+        o = flatbuffers.number_types.UOffsetTFlags.py_type(self._tab.Offset(62))
+        if o != 0:
+            return self._tab.VectorLen(o)
+        return 0
+
+def MonsterStart(builder): builder.StartObject(30)
 def MonsterAddPos(builder, pos): builder.PrependStructSlot(0, flatbuffers.number_types.UOffsetTFlags.py_type(pos), 0)
 def MonsterAddMana(builder, mana): builder.PrependInt16Slot(1, mana, 150)
 def MonsterAddHp(builder, hp): builder.PrependInt16Slot(2, hp, 100)
@@ -333,4 +352,6 @@ def MonsterAddTestf2(builder, testf2): builder.PrependFloat32Slot(26, testf2, 3.
 def MonsterAddTestf3(builder, testf3): builder.PrependFloat32Slot(27, testf3, 0.0)
 def MonsterAddTestarrayofstring2(builder, testarrayofstring2): builder.PrependUOffsetTRelativeSlot(28, flatbuffers.number_types.UOffsetTFlags.py_type(testarrayofstring2), 0)
 def MonsterStartTestarrayofstring2Vector(builder, numElems): return builder.StartVector(4, numElems, 4)
+def MonsterAddTestarrayofsortedstruct(builder, testarrayofsortedstruct): builder.PrependUOffsetTRelativeSlot(29, flatbuffers.number_types.UOffsetTFlags.py_type(testarrayofsortedstruct), 0)
+def MonsterStartTestarrayofsortedstructVector(builder, numElems): return builder.StartVector(8, numElems, 4)
 def MonsterEnd(builder): return builder.EndObject()

tests/monster_test.fbs

@@ -29,6 +29,11 @@ struct Vec3 (force_align: 16) {
   test3:Test;
 }
 
+struct Ability {
+  id:uint(key);
+  distance:uint;
+}
+
 table Stat {
   id:string;
   val:long;
@@ -50,6 +55,7 @@ table Monster {
   testarrayofstring:[string] (id: 10);
   testarrayofstring2:[string] (id: 28);
   testarrayofbools:[bool] (id: 24);
+  testarrayofsortedstruct:[Ability] (id: 29);
   enemy:MyGame.Example.Monster (id:12);  // Test referring by full namespace.
   test:Any (id: 8);
   test4:[Test] (id: 9);

tests/monster_test_generated.h

@@ -23,6 +23,8 @@ struct TestSimpleTableWithEnumT;
 
 struct Vec3;
 
+struct Ability;
+
 struct Stat;
 struct StatT;
 
@@ -247,6 +249,44 @@ MANUALLY_ALIGNED_STRUCT(16) Vec3 FLATBUFFERS_FINAL_CLASS {
 };
 STRUCT_END(Vec3, 32);
 
+MANUALLY_ALIGNED_STRUCT(4) Ability FLATBUFFERS_FINAL_CLASS {
+ private:
+  uint32_t id_;
+  uint32_t distance_;
+
+ public:
+  Ability() {
+    memset(this, 0, sizeof(Ability));
+  }
+  Ability(const Ability &_o) {
+    memcpy(this, &_o, sizeof(Ability));
+  }
+  Ability(uint32_t _id, uint32_t _distance)
+      : id_(flatbuffers::EndianScalar(_id)),
+        distance_(flatbuffers::EndianScalar(_distance)) {
+  }
+  uint32_t id() const {
+    return flatbuffers::EndianScalar(id_);
+  }
+  void mutate_id(uint32_t _id) {
+    flatbuffers::WriteScalar(&id_, _id);
+  }
+  bool KeyCompareLessThan(const Ability *o) const {
+    return id() < o->id();
+  }
+  int KeyCompareWithValue(uint32_t val) const {
+    const auto key = id();
+    return static_cast<int>(key > val) - static_cast<int>(key < val);
+  }
+  uint32_t distance() const {
+    return flatbuffers::EndianScalar(distance_);
+  }
+  void mutate_distance(uint32_t _distance) {
+    flatbuffers::WriteScalar(&distance_, _distance);
+  }
+};
+STRUCT_END(Ability, 8);
+
 }  // namespace Example
 
 namespace Example2 {
@@ -480,6 +520,7 @@ struct MonsterT : public flatbuffers::NativeTable {
   float testf2;
   float testf3;
   std::vector<std::string> testarrayofstring2;
+  std::vector<Ability> testarrayofsortedstruct;
   MonsterT()
       : mana(150),
         hp(100),
@@ -530,7 +571,8 @@ struct Monster FLATBUFFERS_FINAL_CLASS : private flatbuffers::Table {
     VT_TESTF = 54,
     VT_TESTF2 = 56,
     VT_TESTF3 = 58,
-    VT_TESTARRAYOFSTRING2 = 60
+    VT_TESTARRAYOFSTRING2 = 60,
+    VT_TESTARRAYOFSORTEDSTRUCT = 62
   };
   const Vec3 *pos() const {
     return GetStruct<const Vec3 *>(VT_POS);
@@ -722,6 +764,12 @@ struct Monster FLATBUFFERS_FINAL_CLASS : private flatbuffers::Table {
   flatbuffers::Vector<flatbuffers::Offset<flatbuffers::String>> *mutable_testarrayofstring2() {
     return GetPointer<flatbuffers::Vector<flatbuffers::Offset<flatbuffers::String>> *>(VT_TESTARRAYOFSTRING2);
   }
+  const flatbuffers::Vector<const Ability *> *testarrayofsortedstruct() const {
+    return GetPointer<const flatbuffers::Vector<const Ability *> *>(VT_TESTARRAYOFSORTEDSTRUCT);
+  }
+  flatbuffers::Vector<const Ability *> *mutable_testarrayofsortedstruct() {
+    return GetPointer<flatbuffers::Vector<const Ability *> *>(VT_TESTARRAYOFSORTEDSTRUCT);
+  }
   bool Verify(flatbuffers::Verifier &verifier) const {
     return VerifyTableStart(verifier) &&
            VerifyField<Vec3>(verifier, VT_POS) &&
@@ -766,6 +814,8 @@ struct Monster FLATBUFFERS_FINAL_CLASS : private flatbuffers::Table {
            VerifyField<flatbuffers::uoffset_t>(verifier, VT_TESTARRAYOFSTRING2) &&
            verifier.Verify(testarrayofstring2()) &&
            verifier.VerifyVectorOfStrings(testarrayofstring2()) &&
+           VerifyField<flatbuffers::uoffset_t>(verifier, VT_TESTARRAYOFSORTEDSTRUCT) &&
+           verifier.Verify(testarrayofsortedstruct()) &&
            verifier.EndTable();
   }
   MonsterT *UnPack(const flatbuffers::resolver_function_t *_resolver = nullptr) const;
@@ -872,13 +922,16 @@ struct MonsterBuilder {
   void add_testarrayofstring2(flatbuffers::Offset<flatbuffers::Vector<flatbuffers::Offset<flatbuffers::String>>> testarrayofstring2) {
     fbb_.AddOffset(Monster::VT_TESTARRAYOFSTRING2, testarrayofstring2);
   }
+  void add_testarrayofsortedstruct(flatbuffers::Offset<flatbuffers::Vector<const Ability *>> testarrayofsortedstruct) {
+    fbb_.AddOffset(Monster::VT_TESTARRAYOFSORTEDSTRUCT, testarrayofsortedstruct);
+  }
   MonsterBuilder(flatbuffers::FlatBufferBuilder &_fbb)
         : fbb_(_fbb) {
     start_ = fbb_.StartTable();
   }
   MonsterBuilder &operator=(const MonsterBuilder &);
   flatbuffers::Offset<Monster> Finish() {
-    const auto end = fbb_.EndTable(start_, 29);
+    const auto end = fbb_.EndTable(start_, 30);
     auto o = flatbuffers::Offset<Monster>(end);
     fbb_.Required(o, Monster::VT_NAME);
     return o;
@@ -914,12 +967,14 @@ inline flatbuffers::Offset<Monster> CreateMonster(
     float testf = 3.14159f,
     float testf2 = 3.0f,
     float testf3 = 0.0f,
-    flatbuffers::Offset<flatbuffers::Vector<flatbuffers::Offset<flatbuffers::String>>> testarrayofstring2 = 0) {
+    flatbuffers::Offset<flatbuffers::Vector<flatbuffers::Offset<flatbuffers::String>>> testarrayofstring2 = 0,
+    flatbuffers::Offset<flatbuffers::Vector<const Ability *>> testarrayofsortedstruct = 0) {
   MonsterBuilder builder_(_fbb);
   builder_.add_testhashu64_fnv1a(testhashu64_fnv1a);
   builder_.add_testhashs64_fnv1a(testhashs64_fnv1a);
   builder_.add_testhashu64_fnv1(testhashu64_fnv1);
   builder_.add_testhashs64_fnv1(testhashs64_fnv1);
+  builder_.add_testarrayofsortedstruct(testarrayofsortedstruct);
   builder_.add_testarrayofstring2(testarrayofstring2);
   builder_.add_testf3(testf3);
   builder_.add_testf2(testf2);
@@ -976,7 +1031,8 @@ inline flatbuffers::Offset<Monster> CreateMonsterDirect(
     float testf = 3.14159f,
     float testf2 = 3.0f,
     float testf3 = 0.0f,
-    const std::vector<flatbuffers::Offset<flatbuffers::String>> *testarrayofstring2 = nullptr) {
+    const std::vector<flatbuffers::Offset<flatbuffers::String>> *testarrayofstring2 = nullptr,
+    const std::vector<const Ability *> *testarrayofsortedstruct = nullptr) {
   return MyGame::Example::CreateMonster(
       _fbb,
       pos,
@@ -1006,7 +1062,8 @@ inline flatbuffers::Offset<Monster> CreateMonsterDirect(
       testf,
       testf2,
       testf3,
-      testarrayofstring2 ? _fbb.CreateVector<flatbuffers::Offset<flatbuffers::String>>(*testarrayofstring2) : 0);
+      testarrayofstring2 ? _fbb.CreateVector<flatbuffers::Offset<flatbuffers::String>>(*testarrayofstring2) : 0,
+      testarrayofsortedstruct ? _fbb.CreateVector<const Ability *>(*testarrayofsortedstruct) : 0);
 }
 
 flatbuffers::Offset<Monster> CreateMonster(flatbuffers::FlatBufferBuilder &_fbb, const MonsterT *_o, const flatbuffers::rehasher_function_t *_rehasher = nullptr);
@@ -1134,6 +1191,7 @@ inline void Monster::UnPackTo(MonsterT *_o, const flatbuffers::resolver_function
   { auto _e = testf2(); _o->testf2 = _e; };
   { auto _e = testf3(); _o->testf3 = _e; };
   { auto _e = testarrayofstring2(); if (_e) { _o->testarrayofstring2.resize(_e->size()); for (flatbuffers::uoffset_t _i = 0; _i < _e->size(); _i++) { _o->testarrayofstring2[_i] = _e->Get(_i)->str(); } } };
+  { auto _e = testarrayofsortedstruct(); if (_e) { _o->testarrayofsortedstruct.resize(_e->size()); for (flatbuffers::uoffset_t _i = 0; _i < _e->size(); _i++) { _o->testarrayofsortedstruct[_i] = *_e->Get(_i); } } };
 }
 
 inline flatbuffers::Offset<Monster> Monster::Pack(flatbuffers::FlatBufferBuilder &_fbb, const MonsterT* _o, const flatbuffers::rehasher_function_t *_rehasher) {
@@ -1171,6 +1229,7 @@ inline flatbuffers::Offset<Monster> CreateMonster(flatbuffers::FlatBufferBuilder
   auto _testf2 = _o->testf2;
   auto _testf3 = _o->testf3;
   auto _testarrayofstring2 = _o->testarrayofstring2.size() ? _fbb.CreateVectorOfStrings(_o->testarrayofstring2) : 0;
+  auto _testarrayofsortedstruct = _o->testarrayofsortedstruct.size() ? _fbb.CreateVectorOfStructs(_o->testarrayofsortedstruct) : 0;
   return MyGame::Example::CreateMonster(
       _fbb,
       _pos,
@@ -1200,7 +1259,8 @@ inline flatbuffers::Offset<Monster> CreateMonster(flatbuffers::FlatBufferBuilder
       _testf,
       _testf2,
       _testf3,
-      _testarrayofstring2);
+      _testarrayofstring2,
+      _testarrayofsortedstruct);
 }
 
 inline bool VerifyAny(flatbuffers::Verifier &verifier, const void *obj, Any type) {

tests/monster_test_generated.js

@@ -432,6 +432,89 @@ MyGame.Example.Vec3.createVec3 = function(builder, x, y, z, test1, test2, test3_
   return builder.offset();
 };
 
+/**
+ * @constructor
+ */
+MyGame.Example.Ability = function() {
+  /**
+   * @type {flatbuffers.ByteBuffer}
+   */
+  this.bb = null;
+
+  /**
+   * @type {number}
+   */
+  this.bb_pos = 0;
+};
+
+/**
+ * @param {number} i
+ * @param {flatbuffers.ByteBuffer} bb
+ * @returns {MyGame.Example.Ability}
+ */
+MyGame.Example.Ability.prototype.__init = function(i, bb) {
+  this.bb_pos = i;
+  this.bb = bb;
+  return this;
+};
+
+/**
+ * @returns {number}
+ */
+MyGame.Example.Ability.prototype.id = function() {
+  return this.bb.readUint32(this.bb_pos);
+};
+
+/**
+ * @param {number} value
+ * @returns {boolean}
+ */
+MyGame.Example.Ability.prototype.mutate_id = function(value) {
+  var offset = this.bb.__offset(this.bb_pos, 0);
+
+  if (offset === 0) {
+    return false;
+  }
+
+  this.bb.writeUint32(this.bb_pos + offset, value);
+  return true;
+};
+
+/**
+ * @returns {number}
+ */
+MyGame.Example.Ability.prototype.distance = function() {
+  return this.bb.readUint32(this.bb_pos + 4);
+};
+
+/**
+ * @param {number} value
+ * @returns {boolean}
+ */
+MyGame.Example.Ability.prototype.mutate_distance = function(value) {
+  var offset = this.bb.__offset(this.bb_pos, 4);
+
+  if (offset === 0) {
+    return false;
+  }
+
+  this.bb.writeUint32(this.bb_pos + offset, value);
+  return true;
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ * @param {number} id
+ * @param {number} distance
+ * @returns {flatbuffers.Offset}
+ */
+MyGame.Example.Ability.createAbility = function(builder, id, distance) {
+  builder.prep(4, 8);
+  builder.writeInt32(distance);
+  builder.writeInt32(id);
+  return builder.offset();
+};
+
 /**
  * @constructor
  */
@@ -1170,11 +1253,29 @@ MyGame.Example.Monster.prototype.testarrayofstring2Length = function() {
   return offset ? this.bb.__vector_len(this.bb_pos + offset) : 0;
 };
 
+/**
+ * @param {number} index
+ * @param {MyGame.Example.Ability=} obj
+ * @returns {MyGame.Example.Ability}
+ */
+MyGame.Example.Monster.prototype.testarrayofsortedstruct = function(index, obj) {
+  var offset = this.bb.__offset(this.bb_pos, 62);
+  return offset ? (obj || new MyGame.Example.Ability).__init(this.bb.__vector(this.bb_pos + offset) + index * 8, this.bb) : null;
+};
+
+/**
+ * @returns {number}
+ */
+MyGame.Example.Monster.prototype.testarrayofsortedstructLength = function() {
+  var offset = this.bb.__offset(this.bb_pos, 62);
+  return offset ? this.bb.__vector_len(this.bb_pos + offset) : 0;
+};
+
 /**
  * @param {flatbuffers.Builder} builder
  */
 MyGame.Example.Monster.startMonster = function(builder) {
-  builder.startObject(29);
+  builder.startObject(30);
 };
 
 /**
@@ -1535,6 +1636,22 @@ MyGame.Example.Monster.startTestarrayofstring2Vector = function(builder, numElem
   builder.startVector(4, numElems, 4);
 };
 
+/**
+ * @param {flatbuffers.Builder} builder
+ * @param {flatbuffers.Offset} testarrayofsortedstructOffset
+ */
+MyGame.Example.Monster.addTestarrayofsortedstruct = function(builder, testarrayofsortedstructOffset) {
+  builder.addFieldOffset(29, testarrayofsortedstructOffset, 0);
+};
+
+/**
+ * @param {flatbuffers.Builder} builder
+ * @param {number} numElems
+ */
+MyGame.Example.Monster.startTestarrayofsortedstructVector = function(builder, numElems) {
+  builder.startVector(8, numElems, 4);
+};
+
 /**
  * @param {flatbuffers.Builder} builder
  * @returns {flatbuffers.Offset}

tests/test.cpp

@@ -134,12 +134,21 @@ flatbuffers::unique_ptr_t CreateFlatBufferTest(std::string &buffer) {
   // Create an array of sorted tables, can be used with binary search when read:
   auto vecoftables = builder.CreateVectorOfSortedTables(mlocs, 3);
 
+  // Create an array of sorted structs,
+  // can be used with binary search when read:
+  std::vector<Ability> abilities;
+  abilities.push_back(Ability(4, 40));
+  abilities.push_back(Ability(3, 30));
+  abilities.push_back(Ability(2, 20));
+  abilities.push_back(Ability(1, 10));
+  auto vecofstructs = builder.CreateVectorOfSortedStructs(&abilities);
+
   // shortcut for creating monster with all fields set:
   auto mloc = CreateMonster(builder, &vec, 150, 80, name, inventory, Color_Blue,
                             Any_Monster, mlocs[1].Union(), // Store a union.
                             testv, vecofstrings, vecoftables, 0, 0, 0, false,
                             0, 0, 0, 0, 0, 0, 0, 0, 0, 3.14159f, 3.0f, 0.0f,
-                            vecofstrings2);
+                            vecofstrings2, vecofstructs);
 
   FinishMonsterBuffer(builder, mloc);
 
@@ -249,6 +258,18 @@ void AccessFlatBufferTest(const uint8_t *flatbuf, size_t length,
   TEST_NOTNULL(vecoftables->LookupByKey("Fred"));
   TEST_NOTNULL(vecoftables->LookupByKey("Wilma"));
 
+  // Test accessing a vector of sorted structs
+  auto vecofstructs = monster->testarrayofsortedstruct();
+  if (vecofstructs) {  // not filled in monster_test.bfbs
+    for (size_t i = 0; i < vecofstructs->size()-1; i++) {
+      auto left = vecofstructs->Get(i);
+      auto right = vecofstructs->Get(i+1);
+      TEST_EQ(true, (left->KeyCompareLessThan(right)));
+    }
+    TEST_NOTNULL(vecofstructs->LookupByKey(3));
+    TEST_EQ(static_cast<const Ability*>(nullptr), vecofstructs->LookupByKey(5));
+  }
+
   // Since Flatbuffers uses explicit mechanisms to override the default
   // compiler alignment, double check that the compiler indeed obeys them:
   // (Test consists of a short and byte):