Open Radar

 
Summary:
When a function is generic over its return type and there is a mismatch, the error only mentions mismatching arguments.

Steps to Reproduce:
Paste the following code into a swift source file and run swiftc:

protocol Stringable {
  static func string() -> Self
}

final class Box<T> {
  let value: T
  init (_ value: T) {
    self.value = value
  }
}

struct Foo: Stringable {
  let name = "Foo"
  static func string() -> Foo {
    return Foo()
  }
}

struct Bar: Stringable {
  let name = "Bar"
  static func string() -> Bar {
    return Bar()
  }
}

func box<T: Stringable>(string: String) -> Box<T> {
  return Box(T.string())
}

func box<T: Stringable>(string: String) -> Box<[T]> {
  return Box([T.string(), T.string()])
}

let a: Box<Foo> = box("foo")
let b: Box<Bar> = box("bar")
let c: Box<String> = box("baz")

Expected Results:
Expected the code to compile.

Actual Results:
The following error message is given:

ErrorMessages.swift:36:22: error: cannot find an overload for 'box' that accepts an argument list of type '(String)'
let c: Box<String> = box("baz")
                     ^
ErrorMessages.swift:36:22: note: overloads for 'box' exist with these partially matching parameter lists: (String)
let c: Box<String> = box("baz")
                     ^

Regression:
N/A

Notes:
The issue still appears to be present in Xcode 7 beta 4.