Is this a relatively new language change? When I try it with the version of
Swift that comes with Xcode 7.3.1, I get
error: same-type requirement makes generic parameters 'T1' and 'T2'
equivalent
extension Foo where T1 == T2 {
^
> On May 15, 2016, at 1:33 PM, Karl <razie...@gmail.com> wrote:
>
> Yes. You need to put it in an extension.
>
> extension Foo where T1 == T2 {
> convenience init(values: [T1]){
> ….
> }
> }
>
>> On 15 May 2016, at 14:45, Neil Faiman via swift-users
>> <swift-users@swift.org> wrote:
>>
>> Is it possible for a generic class to have methods (specifically,
>> initializers) which are only defined if the generic parameters meet certain
>> constratins?
>>
>> Here’s a concrete example:
>>
>> class Foo <T1, T2> {
>> init(pairs: [(T1, T2)]) {}
>> // What I’d like to be able to doL
>> convenience init "where T1 == T2" (values: [T1]) { self.init(pairs:
>> values.map{ ($0, $0) }) }
>> }
>>
>> That is, I’d like to provide a convenience initializer that takes an array
>> of values instead of pairs, and turns the values into pairs, IF THE TWO
>> GENERIC TYPE PARAMETERS ARE THE SAME.
>>
>> I can’t find a way to accomplish this. Is there one?
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