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diff --git a/lib/std/isolation.nim b/lib/std/isolation.nim
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+#
+#
+#            Nim's Runtime Library
+#        (c) Copyright 2020 Nim contributors
+#
+#    See the file "copying.txt", included in this
+#    distribution, for details about the copyright.
+#
+
+## This module implements the `Isolated[T]` type for
+## safe construction of isolated subgraphs that can be
+## passed efficiently to different channels and threads.
+##
+## .. warning:: This module is experimental and its interface may change.
+##
+
+type
+  Isolated*[T] {.sendable.} = object ## Isolated data can only be moved, not copied.
+    value: T
+
+proc `=copy`*[T](dest: var Isolated[T]; src: Isolated[T]) {.error.}
+
+proc `=sink`*[T](dest: var Isolated[T]; src: Isolated[T]) {.inline.} =
+  # delegate to value's sink operation
+  `=sink`(dest.value, src.value)
+
+proc `=destroy`*[T](dest: var Isolated[T]) {.inline.} =
+  # delegate to value's destroy operation
+  `=destroy`(dest.value)
+
+func isolate*[T](value: sink T): Isolated[T] {.magic: "Isolate".} =
+  ## Creates an isolated subgraph from the expression `value`.
+  ## Isolation is checked at compile time.
+  ##
+  ## Please read https://github.com/nim-lang/RFCs/issues/244
+  ## for more details.
+  Isolated[T](value: value)
+
+func unsafeIsolate*[T](value: sink T): Isolated[T] =
+  ## Creates an isolated subgraph from the expression `value`.
+  ##
+  ## .. warning:: The proc doesn't check whether `value` is isolated.
+  ##
+  Isolated[T](value: value)
+
+func extract*[T](src: var Isolated[T]): T =
+  ## Returns the internal value of `src`.
+  ## The value is moved from `src`.
+  result = move(src.value)