1 files changed, 22 insertions, 24 deletions
diff --git a/lib/pure/asyncfutures.nim b/lib/pure/asyncfutures.nim
index 035b6182d..29ebf8f89 100644
--- a/lib/pure/asyncfutures.nim
+++ b/lib/pure/asyncfutures.nim
@@ -7,7 +7,7 @@
 #    distribution, for details about the copyright.
 #
 
-import os, tables, strutils, times, heapqueue, options, deques, cstrutils
+import std/[os, tables, strutils, times, heapqueue, options, deques, cstrutils, typetraits]
 
 import system/stacktraces
 
@@ -29,7 +29,7 @@ type
     finished: bool
     error*: ref Exception              ## Stored exception
     errorStackTrace*: string
-    when not defined(release):
+    when not defined(release) or defined(futureLogging):
       stackTrace: seq[StackTraceEntry] ## For debugging purposes only.
       id: int
       fromProc: string
@@ -51,7 +51,7 @@ const
   NimAsyncContinueSuffix* = "NimAsyncContinue" ## For internal usage. Do not use.
 
 when isFutureLoggingEnabled:
-  import hashes
+  import std/hashes
   type
     FutureInfo* = object
       stackTrace*: seq[StackTraceEntry]
@@ -193,7 +193,7 @@ proc add(callbacks: var CallbackList, function: CallbackFunc) =
         last = last.next
       last.next = newCallback
 
-proc completeImpl[T, U](future: Future[T], val: U, isVoid: static bool) =
+proc completeImpl[T, U](future: Future[T], val: sink U, isVoid: static bool) =
   #assert(not future.finished, "Future already finished, cannot finish twice.")
   checkFinished(future)
   assert(future.error == nil)
@@ -203,7 +203,7 @@ proc completeImpl[T, U](future: Future[T], val: U, isVoid: static bool) =
   future.callbacks.call()
   when isFutureLoggingEnabled: logFutureFinish(future)
 
-proc complete*[T](future: Future[T], val: T) =
+proc complete*[T](future: Future[T], val: sink T) =
   ## Completes `future` with value `val`.
   completeImpl(future, val, false)
 
@@ -219,7 +219,7 @@ proc complete*[T](future: FutureVar[T]) =
   fut.callbacks.call()
   when isFutureLoggingEnabled: logFutureFinish(Future[T](future))
 
-proc complete*[T](future: FutureVar[T], val: T) =
+proc complete*[T](future: FutureVar[T], val: sink T) =
   ## Completes a `FutureVar` with value `val`.
   ##
   ## Any previously stored value will be overwritten.
@@ -329,29 +329,21 @@ proc `$`*(stackTraceEntries: seq[StackTraceEntry]): string =
     if leftLen > longestLeft:
       longestLeft = leftLen
 
-  var indent = 2
   # Format the entries.
   for entry in entries:
     let (filename, procname) = getFilenameProcname(entry)
 
-    if procname == "":
-      if entry.line == reraisedFromBegin:
-        result.add(spaces(indent) & "#[\n")
-        indent.inc(2)
-      elif entry.line == reraisedFromEnd:
-        indent.dec(2)
-        result.add(spaces(indent) & "]#\n")
-      continue
+    if procname == "" and entry.line == reraisedFromBegin:
+      break
 
     let left = "$#($#)" % [filename, $entry.line]
-    result.add((spaces(indent) & "$#$# $#\n") % [
+    result.add((spaces(2) & "$# $#\n") % [
       left,
-      spaces(longestLeft - left.len + 2),
       procname
     ])
     let hint = getHint(entry)
     if hint.len > 0:
-      result.add(spaces(indent+2) & "## " & hint & "\n")
+      result.add(spaces(4) & "## " & hint & "\n")
 
 proc injectStacktrace[T](future: Future[T]) =
   when not defined(release):
@@ -378,11 +370,7 @@ proc injectStacktrace[T](future: Future[T]) =
     #   newMsg.add "\n" & $entry
     future.error.msg = newMsg
 
-proc read*[T](future: Future[T] | FutureVar[T]): T =
-  ## Retrieves the value of `future`. Future must be finished otherwise
-  ## this function will fail with a `ValueError` exception.
-  ##
-  ## If the result of the future is an error then that error will be raised.
+template readImpl(future, T) =
   when future is Future[T]:
     let fut {.cursor.} = future
   else:
@@ -392,11 +380,21 @@ proc read*[T](future: Future[T] | FutureVar[T]): T =
       injectStacktrace(fut)
       raise fut.error
     when T isnot void:
-      result = fut.value
+      result = distinctBase(future).value
   else:
     # TODO: Make a custom exception type for this?
     raise newException(ValueError, "Future still in progress.")
 
+proc read*[T](future: Future[T] | FutureVar[T]): lent T =
+  ## Retrieves the value of `future`. Future must be finished otherwise
+  ## this function will fail with a `ValueError` exception.
+  ##
+  ## If the result of the future is an error then that error will be raised.
+  readImpl(future, T)
+
+proc read*(future: Future[void] | FutureVar[void]) =
+  readImpl(future, void)
+
 proc readError*[T](future: Future[T]): ref Exception =
   ## Retrieves the exception stored in `future`.
   ##