[SR-6305] Cannot initialise Dictionary from an EnumeratedSequence #48855

karwa · 2017-11-06T12:22:56Z

Environment

Apple Swift version 4.0.3 (swiftlang-900.0.71 clang-900.0.38)

Target: x86_64-apple-macosx10.9

Additional Detail from JIRA

md5: a219796b79b304ec98d478ac6a4adc11

is duplicated by:

SR-6905 Dictionary(uniqueKeysWithValues:) does not accept sequence of labeled tuples

Issue Description:

The following snippet fails to compile:

let test = Dictionary(uniqueKeysWithValues: ["a", "b", "c"].enumerated())

With the message:

Cannot invoke initializer for type 'Dictionary<_, _>' with an argument list of type '(uniqueKeysWithValues: EnumeratedSequence<[String]>)'

The only way I was able to get it to work was to add a pass-through call to "map" on the end:

let test = Dictionary(uniqueKeysWithValues: ["a", "b", "c"].enumerated().map { $0 })

The text was updated successfully, but these errors were encountered:

belkadan · 2017-11-06T17:17:26Z

belkadan · 2017-11-06T17:22:45Z

(thanks, Karl!)

belkadan · 2018-02-02T18:04:27Z

swift-ci · 2018-08-16T13:00:13Z

Comment by Manuel Martín Benítez (JIRA)

You are just passing a Sequence to the initializer with the keys, and it needs a sequence with key-value pairs.

let test = Dictionary(uniqueKeysWithValues: zip(["a", "b", "c"], [1, 2, 3]))

swift-ci transferred this issue from apple/swift-issues Apr 25, 2022

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