add flatbuffers

commit 6da1cf79d90eb242e7da5318241d42279a3df3ba
Author: Max Burke <max@urbanlogiq.com>
Date:   Sun Jan 19 14:47:28 2020 -0800

    [rust] Add use declarations to Rust-generated bindings for imported FB definitions (#5645)

    * Bugfix for Rust generation of union fields named with language keywords

flatbuffers/swift/Sources/FlatBuffers/FlatBufferObject.swift

@@ -0,0 +1,87 @@
+import Foundation
+
+/// FlatbufferObject structures all the Flatbuffers objects
+public protocol FlatBufferObject {
+    init(_ bb: ByteBuffer, o: Int32)
+}
+
+/// Readable is structures all the Flatbuffers structs
+///
+/// Readable is a procotol that each Flatbuffer struct should confirm to since
+/// FlatBufferBuilder would require a Type to both create(struct:) and createVector(structs:) functions
+public protocol Readable: FlatBufferObject {
+    static var size: Int { get }
+    static var alignment: Int { get }
+}
+
+public protocol Enum {
+    associatedtype T: Scalar
+    static var byteSize: Int { get }
+    var value: T { get }
+}
+
+/// Mutable is a protocol that allows us to mutate Scalar values within the buffer
+public protocol Mutable {
+    /// makes Flatbuffer accessed within the Protocol
+    var bb: ByteBuffer { get }
+    /// makes position of the table/struct  accessed within the Protocol
+    var postion: Int32 { get }
+}
+
+extension Mutable {
+    
+    /// Mutates the memory in the buffer, this is only called from the access function of table and structs
+    /// - Parameters:
+    ///   - value: New value to be inserted to the buffer
+    ///   - index: index of the Element
+    func mutate<T: Scalar>(value: T, o: Int32) -> Bool {
+        guard o != 0 else { return false }
+        bb.write(value: value, index: Int(o), direct: true)
+        return true
+    }
+}
+
+extension Mutable where Self == Table {
+    
+    /// Mutates a value by calling mutate with respect to the position in the table
+    /// - Parameters:
+    ///   - value: New value to be inserted to the buffer
+    ///   - index: index of the Element
+    public func mutate<T: Scalar>(_ value: T, index: Int32) -> Bool {
+        guard index != 0 else { return false }
+        return mutate(value: value, o: index + postion)
+    }
+    
+    /// Directly mutates the element by calling mutate
+    ///
+    /// Mutates the Element at index ignoring the current position by calling mutate
+    /// - Parameters:
+    ///   - value: New value to be inserted to the buffer
+    ///   - index: index of the Element
+    public func directMutate<T: Scalar>(_ value: T, index: Int32) -> Bool {
+        return mutate(value: value, o: index)
+    }
+}
+
+extension Mutable where Self == Struct {
+    
+    /// Mutates a value by calling mutate with respect to the position in the struct
+    /// - Parameters:
+    ///   - value: New value to be inserted to the buffer
+    ///   - index: index of the Element
+    public func mutate<T: Scalar>(_ value: T, index: Int32) -> Bool {
+        return mutate(value: value, o: index + postion)
+    }
+    
+    /// Directly mutates the element by calling mutate
+    ///
+    /// Mutates the Element at index ignoring the current position by calling mutate
+    /// - Parameters:
+    ///   - value: New value to be inserted to the buffer
+    ///   - index: index of the Element
+    public func directMutate<T: Scalar>(_ value: T, index: Int32) -> Bool {
+        return mutate(value: value, o: index)
+    }
+}
+extension Struct: Mutable {}
+extension Table: Mutable {}