How to assign an int variable to a request parameter?

Question

In the following snippet test1() compiles, test2() doesn't. How to assign a variable of type Int to a request parameter?

Swift version 3.1.1 (swift-3.1.1-RELEASE) Target: x86_64-unknown-linux-gnu

import Testing
import HTTP

func test1() throws {
    let req = Request.makeTest(method: .get)
    //OK compiles
    req.parameters["id"] = 1
}

func test2() throws {
    let req = Request.makeTest(method: .get)
    let id = 1
    // NOK doesn't compile
    // compiler error:
    // /path/to/file.swift:12:28: error: cannot assign value of type 'Int' to type 'Parameters?'
    // req.parameters["id"] = id
    //                        ^~
    req.parameters["id"] = id
}

Answer 1

That's because 1 isn't an int. It's a thing that can be converted to various types (for example Int, Int32, Float, Double, UInt and so on), and the compiler will figure out whether it can be converted to a type that makes the call work. In the second case, the compiler decided when you assigned to id that id would be an Int. And apparently an Int cannot be assigned to Parameters?

Answer 2

Try the following (works with Swift 4, Vapor 2):

func test2() throws {
    let req = Request.makeTest(method: .get)
    let id = 1
    req.parameters["id"] = Parameters(id)
}