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outParamsAt macro for easy writing code that works with both 2.0 and 1.x.
macro outParamsAt(positions: static openArray[int]; n: untyped): untyped
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Use this macro to annotate out parameters in a portable way.
Example:
proc p(x: var int) {.outParamsAt: [1].} =
discard "x is really an 'out int' if the Nim compiler supports 'out' parameters"
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