[Codegen][Swift] Generic specialization of Decoders.decode func doesn't work

Decoders class have several specializations for decodable type:

• T - (object or primitive type)
• [T] - (array)
• [Key:T] - (dictionary)

Here there are:

static func decode<T>(clazz clazz: [T].Type, source: AnyObject) -> [T] { ... }
static func decode<T, Key: Hashable>(clazz clazz: [Key:T].Type, source: AnyObject) -> [Key:T] { ... }
static func decode<T>(clazz clazz: T.Type, source: AnyObject) -> T { ...  }

Actually, only the last specialization is invoked, even on arrays (which type is printed in log as Array). Seems a problem with a type deduction in swift generics.

i'm using:

• Xcode 7.0.1 (7A1001)
• Swift 2.0

Start by reproducing the generated Swift client behavior with the Decoders.decode overloads shown in the issue, using the stated Swift 2.0 and Xcode 7.0.1 versions if available. Inspect why array and dictionary values select the generic T overload; done when the appropriate specialized overload is selected for each supported decoded type.