[Swift] Rebuild the way swift handles structs from scratch (#6326)

* Rebuild the way swift handles structs from scratch

* Updates docs, and sample binary

* Replaces InMemory to Mutable

* Migrates docs from inmemory

* use inline for some functions

* Renamed Mutable objects

* Updates documentation

docs/source/Tutorial.md

@@ -544,10 +544,10 @@ The first step is to import/include the library, generated files, etc.
   import Flatbuffers
 
   // typealiases for convenience
-  typealias Monster = MyGame1.Sample.Monster
-  typealias Weapon = MyGame1.Sample.Weapon
-  typealias Color = MyGame1.Sample.Color
-  typealias Vec3 = MyGame1.Sample.Vec3
+  typealias Monster = MyGame1_Sample_Monster
+  typealias Weapon = MyGame1_Sample_Weapon
+  typealias Color = MyGame1_Sample_Color
+  typealias Vec3 = MyGame1_Sample_Vec3
 ~~~
 </div>
 
@@ -1420,9 +1420,20 @@ for the `path` field above:
 <div class="language-swift">
 ~~~{.swift}
   //
-  Monster.startVectorOfvec3(2, in: &fbb)
-  MyGame_Example_Vec3.createVec3(builder: &fbb, x: 1, y: 2, z: 3)
-  MyGame_Example_Vec3.createVec3(builder: &fbb, x: 4, y: 5, z: 6)
+  let points = fbb.createVector(ofStructs: [
+    Vec3(x: 1, y: 2, z: 3),
+    Vec3(x: 4, y: 5, z: 6)
+  ])
+
+  // OR
+  var vec3 = [
+    Vec3(x: 1, y: 2, z: 3),
+    Vec3(x: 4, y: 5, z: 6)
+  ]
+  Monster.startVectorOfVec3(2, in: &fbb)
+  for i in obj {
+    _ = create(struct: i)
+  }
   let points = fbb.endVectorOfStructs(count: size)
 ~~~
 </div>
@@ -1702,17 +1713,16 @@ can serialize the monster itself:
 </div>
 <div class="language-swift">
 ~~~{.swift}
-  let start = Monster.startMonster(&builder)
-  let posStruct = MyGame_Example_Vec3.createVec3(builder: &builder, x: 1, y: 2, z: 3)
-  Monster.add(pos: pos, &builder)
-  Monster.add(hp: 300, &builder)
-  Monster.add(name: name, &builder)
-  Monster.addVectorOf(inventory: inventoryOffset, &builder)
-  Monster.add(color: .red, &builder)
-  Monster.addVectorOf(weapons: weaponsOffset, &builder)
-  Monster.add(equippedType: .weapon, &builder)
-  Monster.add(equipped: axe, &builder)
-  var orc = Monster.endMonster(&builder, start: start)
+  let orc = Monster.createMonster(
+    fbb: &builder,
+    pos: Vec3(x: 1, y: 2, z: 3),
+    hp: 300,
+    name: name,
+    inventory: inventoryOffset,
+    color: .red,
+    weapons: weaponsOffset,
+    equippedType: .weapon,
+    equipped: axe)
 ~~~
 </div>
 
@@ -1780,6 +1790,21 @@ a bit more flexibility.
 ~~~
 </div>
 
+<div class="language-swift">
+~~~{.swift}
+  let start = Monster.startMonster(&builder)
+  Monster.add(pos: Vec3(x: 1, y: 2, z: 3), &builder)
+  Monster.add(hp: 300, &builder)
+  Monster.add(name: name, &builder)
+  Monster.addVectorOf(inventory: inventoryOffset, &builder)
+  Monster.add(color: .red, &builder)
+  Monster.addVectorOf(weapons: weaponsOffset, &builder)
+  Monster.add(equippedType: .weapon, &builder)
+  Monster.add(equipped: axe, &builder)
+  var orc = Monster.endMonster(&builder, start: start)
+~~~
+</div>
+
 Before finishing the serialization, let's take a quick look at FlatBuffer
 `union Equipped`. There are two parts to each FlatBuffer `union`. The first is
 a hidden field `_type` that is generated to hold the type of `table` referred
@@ -3239,7 +3264,8 @@ mutators like so:
 ~~~{.swift}
   let monster = Monster.getRootAsMonster(bb: ByteBuffer(bytes: buf))
   monster.mutate(hp: 10) // mutates a value in a table
-  monster.pos.mutate(z: 4) // mutates a value in a struct
+  /// to mutate structs in swift you have to use the mutable accessors
+  monster.mutablePos.mutate(z: 4) // mutates a value in a struct
   monster.mutate(inventory: 6, at index: 0) // mutates a value in an Scalar array
 ~~~
 </div>