swift - 'Ambiguous reference' when using joinWithSeparator to intersperse into array -

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i'm trying use joinwithseparator insert separator element between elements of array. based on documentation, should able do:

[1, 2, 3].joinwithseparator([0])

to get:

[1, 0, 2, 0, 3]

instead, get:

repl.swift:3:11: error: type of expression ambiguous without more context [1, 2, 3].joinwithseparator([0])

how can this?

joinwithseparator not work this. input should sequence of sequence i.e.

// swift 2: [[1], [2], [3]].joinwithseparator([0]) // lazy sequence give `[1, 0, 2, 0, 3]`.  // swift 3: [[1], [2], [3]].joined(separator: [0])

you intersperse flatmap , drop last separator:

// swift 2 , 3: [1, 2, 3].flatmap { [$0, 0] }.droplast()

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