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Summary:
The following code snippet fails to compile with the compiler complaining that 'Test' does not conform to SequenceType.

If a non-generic generator that wraps 'Test' instead of a generic 'TestType' is used, this compiles successfully.
This also compiles if 'TestType' does not require SequenceType conformance.

An example project is attached.

struct Test : TestType {
    var storage: [Int] = []

    mutating func pop() -> Int? {
        return storage.popLast()
    }
}


extension Test : SequenceType {
    func generate() -> TestGenerator<Test> {
        return TestGenerator(self)
    }
}


public protocol TestType : SequenceType {
    mutating func pop() -> Int?
}

struct TestGenerator<T : TestType> : GeneratorType {
    private var content: T
    
    init(_ content: T) {
        self.content = content
    }
    
    mutating func next() -> Int? {
        return content.pop()
    }
}

Steps to Reproduce:
1) Open the attached project
2) Build

Expected Results:
The given code should compile successfully.

Actual Results:
Compilation fails with: "Type 'Test' does not conform to protocol 'SequenceType'".

Version:
OS X 10.11 (15A282b)
Version 7.1 beta (7B60)
Apple Swift version 2.0 (swiftlang_PONDEROSA-700.1.100.2 clang-700.1.74)