[swift-users] comparison Non-Optional and Optional without unwrap

[Rien]

Because the comparison function “==“ has the signature: 

func ==<T : Equatable>(lhs: T?, rhs: T?) -> Bool

An optional parameter accepts non-optionals. In a sense non-optionals are “promoted” to optionals when used for an optional parameter.

Rien.

> On 18 Oct 2016, at 10:58, Седых Александр via swift-users <swift-users at swift.org> wrote:
> 
> This code work: 
> 
> let one: Int? = 5
> let two = 5
> let result = one == two
>  
> print(result)
> 
> //print true
> 
> Why we can access to Optional value without unwrap within comparison operations?
> 
> -- 
> Седых Александр
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