The Error with Codable in nested type in generic type

Using Swift
1

Hello
I want to make universal json exporter structure, and Swift drop my venture.
The code below

import Foundation

public protocol Sizeble {
    var weight: Double { get }
    var widht: Double { get }
    var height: Double { get }
}

public struct Bike: Sizeble  {
    public var weight: Double = 100.0
    public var widht: Double = 15
    public var height: Double = 5
    public init() {}
}

public struct ExportWraper<Base>{
    public var base: Base
    public init(base: Base) {
        self.base = base
    }
}

extension ExportWraper where Base: Sizeble {
    public struct Export: Codable {
        public let weight: Double
        public let width: Double
        public let height: Double
        init(base: Base) {
            weight = base.weight
            width = base.widht
            height = base.height
        }
    }
    public var export: Export { return Export(base: base) }
}

let bike = Bike()
let wraper = ExportWraper(base: bike)
let exporter = wraper.export

let encoder = JSONEncoder()
encoder.outputFormatting = .prettyPrinted
do {

    let data = try encoder.encode(exporter)

error: Execution was interrupted, reason: EXC_BAD_ACCESS (code=EXC_I386_GPFLT).
The process has been left at the point where it was interrupted, use "thread return -x" to return to the  
state before expression evaluation.

} catch let error {
    print(error)
}

What I do wrong?

2

Hi Alex, it doesn't look like you're doing anything wrong; this works fine for me in Swift 4.1. Adding a print line

let data = try encoder.encode(exporter)
print(String(data: data, encoding: .utf8)!)

results in

{
  "width" : 15,
  "height" : 5,
  "weight" : 100
}

If you are able to reproduce this consistently, do you mind please filing a bug report so we can investigate?

3

Thanks. I'm still on Swift 4.0.3. Tomorrow will update to 4.1. What is best way to update, just install Xcode beta?

4

Yes, though this shouldn't happen in Swift 4.0.3 either... Please update this if you still see it in 4.1.