diff --git a/lib/pure/collections/critbits.nim b/lib/pure/collections/critbits.nim
index 3d10e39aa..fb5fd7f36 100644
--- a/lib/pure/collections/critbits.nim
+++ b/lib/pure/collections/critbits.nim
@@ -17,11 +17,11 @@ type
     otherbits: char
     case isLeaf: bool
     of false: child: array[0..1, ref NodeObj[T]]
-    of true: 
+    of true:
       key: string
       when T isnot void:
         val: T
-    
+
   Node[T] = ref NodeObj[T]
   CritBitTree*[T] = object ## The crit bit tree can either be used
                            ## as a mapping from strings to
@@ -66,7 +66,7 @@ proc rawInsert[T](c: var CritBitTree[T], key: string): Node[T] =
       let ch = if it.byte < key.len: key[it.byte] else: '\0'
       let dir = (1 + (ch.ord or it.otherBits.ord)) shr 8
       it = it.child[dir]
-    
+
     var newOtherBits = 0
     var newByte = 0
     block blockX:
@@ -84,7 +84,7 @@ proc rawInsert[T](c: var CritBitTree[T], key: string): Node[T] =
     newOtherBits = newOtherBits xor 255
     let ch = it.key[newByte]
     let dir = (1 + (ord(ch) or newOtherBits)) shr 8
-    
+
     var inner: Node[T]
     new inner
     new result
@@ -93,7 +93,7 @@ proc rawInsert[T](c: var CritBitTree[T], key: string): Node[T] =
     inner.otherBits = chr(newOtherBits)
     inner.byte = newByte
     inner.child[1 - dir] = result
-    
+
     var wherep = addr(c.root)
     while true:
       var p = wherep[]
@@ -132,20 +132,31 @@ proc `[]=`*[T](c: var CritBitTree[T], key: string, val: T) =
   var n = rawInsert(c, key)
   n.val = val
 
-proc `[]`*[T](c: CritBitTree[T], key: string): T {.inline.} =
-  ## retrieves the value at ``c[key]``. If `key` is not in `t`,
-  ## default empty value for the type `B` is returned
-  ## and no exception is raised. One can check with ``hasKey`` whether the key
-  ## exists.
+template get[T](c: CritBitTree[T], key: string): T {.immediate.} =
   let n = rawGet(c, key)
   if n != nil: result = n.val
+  else:
+    when compiles($key):
+      raise newException(KeyError, "key not found: " & $key)
+    else:
+      raise newException(KeyError, "key not found")
+
+proc `[]`*[T](c: CritBitTree[T], key: string): T {.inline.} =
+  ## retrieves the value at ``c[key]``. If `key` is not in `t`, the
+  ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
+  ## the key exists.
+  get(c, key)
 
-proc mget*[T](c: var CritBitTree[T], key: string): var T {.inline.} =
+proc `[]`*[T](c: var CritBitTree[T], key: string): var T {.inline.} =
   ## retrieves the value at ``c[key]``. The value can be modified.
   ## If `key` is not in `t`, the ``KeyError`` exception is raised.
-  let n = rawGet(c, key)
-  if n != nil: result = n.val
-  else: raise newException(KeyError, "key not found: " & $key)
+  get(c, key)
+
+proc mget*[T](c: var CritBitTree[T], key: string): var T {.inline, deprecated.} =
+  ## retrieves the value at ``c[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  ## Use ```[]``` instead.
+  get(c, key)
 
 proc excl*[T](c: var CritBitTree[T], key: string) =
   ## removes `key` (and its associated value) from the set `c`.
@@ -176,7 +187,7 @@ iterator leaves[T](n: Node[T]): Node[T] =
     # XXX actually we could compute the necessary stack size in advance:
     # it's roughly log2(c.count).
     var stack = @[n]
-    while stack.len > 0: 
+    while stack.len > 0:
       var it = stack.pop
       while not it.isLeaf:
         stack.add(it.child[1])
@@ -205,7 +216,7 @@ iterator items*[T](c: CritBitTree[T]): string =
 iterator pairs*[T](c: CritBitTree[T]): tuple[key: string, val: T] =
   ## yields all (key, value)-pairs of `c`.
   for x in leaves(c.root): yield (x.key, x.val)
-  
+
 iterator mpairs*[T](c: var CritBitTree[T]): tuple[key: string, val: var T] =
   ## yields all (key, value)-pairs of `c`. The yielded values can be modified.
   for x in leaves(c.root): yield (x.key, x.val)
@@ -251,7 +262,7 @@ iterator pairsWithPrefix*[T](c: CritBitTree[T],
   ## yields all (key, value)-pairs of `c` starting with `prefix`.
   let top = allprefixedAux(c, prefix)
   for x in leaves(top): yield (x.key, x.val)
-  
+
 iterator mpairsWithPrefix*[T](c: var CritBitTree[T],
                               prefix: string): tuple[key: string, val: var T] =
   ## yields all (key, value)-pairs of `c` starting with `prefix`.
@@ -297,7 +308,6 @@ when isMainModule:
 
   for w in r.items:
     echo w
-    
+
   for w in r.itemsWithPrefix("de"):
     echo w
-
diff --git a/lib/pure/collections/sets.nim b/lib/pure/collections/sets.nim
index 4a20d00a4..49271e2c9 100644
--- a/lib/pure/collections/sets.nim
+++ b/lib/pure/collections/sets.nim
@@ -154,7 +154,7 @@ proc rawGetKnownHC[A](s: HashSet[A], key: A, hc: THash): int {.inline.} =
 proc rawGet[A](s: HashSet[A], key: A, hc: var THash): int {.inline.} =
   rawGetImpl()
 
-proc mget*[A](s: var HashSet[A], key: A): var A =
+proc `[]`*[A](s: var HashSet[A], key: A): var A =
   ## returns the element that is actually stored in 's' which has the same
   ## value as 'key' or raises the ``EInvalidKey`` exception. This is useful
   ## when one overloaded 'hash' and '==' but still needs reference semantics
@@ -165,6 +165,13 @@ proc mget*[A](s: var HashSet[A], key: A): var A =
   if index >= 0: result = s.data[index].key
   else: raise newException(KeyError, "key not found: " & $key)
 
+proc mget*[A](s: var HashSet[A], key: A): var A {.deprecated.} =
+  ## returns the element that is actually stored in 's' which has the same
+  ## value as 'key' or raises the ``EInvalidKey`` exception. This is useful
+  ## when one overloaded 'hash' and '==' but still needs reference semantics
+  ## for sharing. Use ```[]``` instead.
+  s[key]
+
 proc contains*[A](s: HashSet[A], key: A): bool =
   ## Returns true iff `key` is in `s`.
   ##
diff --git a/lib/pure/collections/tables.nim b/lib/pure/collections/tables.nim
index f85acef22..adc9c6d8d 100644
--- a/lib/pure/collections/tables.nim
+++ b/lib/pure/collections/tables.nim
@@ -181,18 +181,7 @@ proc rawGetDeep[A, B](t: Table[A, B], key: A, hc: var THash): int {.inline.} =
 proc rawGet[A, B](t: Table[A, B], key: A, hc: var THash): int {.inline.} =
   rawGetImpl()
 
-proc `[]`*[A, B](t: Table[A, B], key: A): B =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
-  ## default empty value for the type `B` is returned
-  ## and no exception is raised. One can check with ``hasKey`` whether the key
-  ## exists.
-  var hc: THash
-  var index = rawGet(t, key, hc)
-  if index >= 0: result = t.data[index].val
-
-proc mget*[A, B](t: var Table[A, B], key: A): var B =
-  ## retrieves the value at ``t[key]``. The value can be modified.
-  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+template get[A, B](t: Table[A, B], key: A): B {.immediate.} =
   var hc: THash
   var index = rawGet(t, key, hc)
   if index >= 0: result = t.data[index].val
@@ -202,6 +191,23 @@ proc mget*[A, B](t: var Table[A, B], key: A): var B =
     else:
       raise newException(KeyError, "key not found")
 
+proc `[]`*[A, B](t: Table[A, B], key: A): B =
+  ## retrieves the value at ``t[key]``. If `key` is not in `t`, the
+  ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
+  ## the key exists.
+  get(t, key)
+
+proc `[]`*[A, B](t: var Table[A, B], key: A): var B =
+  ## retrieves the value at ``t[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  get(t, key)
+
+proc mget*[A, B](t: var Table[A, B], key: A): var B {.deprecated.} =
+  ## retrieves the value at ``t[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised. Use ```[]```
+  ## instead.
+  get(t, key)
+
 iterator allValues*[A, B](t: Table[A, B]; key: A): B =
   ## iterates over any value in the table `t` that belongs to the given `key`.
   var h: THash = hash(key) and high(t.data)
@@ -386,17 +392,17 @@ iterator mvalues*[A, B](t: TableRef[A, B]): var B =
   for h in 0..high(t.data):
     if isFilled(t.data[h].hcode): yield t.data[h].val
 
-proc `[]`*[A, B](t: TableRef[A, B], key: A): B =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
-  ## default empty value for the type `B` is returned
-  ## and no exception is raised. One can check with ``hasKey`` whether the key
-  ## exists.
+proc `[]`*[A, B](t: TableRef[A, B], key: A): var B =
+  ## retrieves the value at ``t[key]``.  If `key` is not in `t`, the
+  ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
+  ## the key exists.
   result = t[][key]
 
-proc mget*[A, B](t: TableRef[A, B], key: A): var B =
+proc mget*[A, B](t: TableRef[A, B], key: A): var B {.deprecated.} =
   ## retrieves the value at ``t[key]``. The value can be modified.
-  ## If `key` is not in `t`, the ``EInvalidKey`` exception is raised.
-  t[].mget(key)
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  ## Use ```[]``` instead.
+  t[][key]
 
 proc mgetOrPut*[A, B](t: TableRef[A, B], key: A, val: B): var B =
   ## retrieves value at ``t[key]`` or puts ``val`` if not present, either way
@@ -510,22 +516,32 @@ proc rawGetDeep[A, B](t: OrderedTable[A, B], key: A, hc: var THash): int {.inlin
 proc rawGet[A, B](t: OrderedTable[A, B], key: A, hc: var THash): int =
   rawGetImpl()
 
-proc `[]`*[A, B](t: OrderedTable[A, B], key: A): B =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
-  ## default empty value for the type `B` is returned
-  ## and no exception is raised. One can check with ``hasKey`` whether the key
-  ## exists.
+template get[A, B](t: OrderedTable[A, B], key: A): B {.immediate.} =
   var hc: THash
   var index = rawGet(t, key, hc)
   if index >= 0: result = t.data[index].val
+  else:
+    when compiles($key):
+      raise newException(KeyError, "key not found: " & $key)
+    else:
+      raise newException(KeyError, "key not found")
+
+proc `[]`*[A, B](t: OrderedTable[A, B], key: A): B =
+  ## retrieves the value at ``t[key]``. If `key` is not in `t`, the
+  ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
+  ## the key exists.
+  get(t, key)
 
-proc mget*[A, B](t: var OrderedTable[A, B], key: A): var B =
+proc `[]`*[A, B](t: var OrderedTable[A, B], key: A): var B =
   ## retrieves the value at ``t[key]``. The value can be modified.
-  ## If `key` is not in `t`, the ``EInvalidKey`` exception is raised.
-  var hc: THash
-  var index = rawGet(t, key, hc)
-  if index >= 0: result = t.data[index].val
-  else: raise newException(KeyError, "key not found: " & $key)
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  get(t, key)
+
+proc mget*[A, B](t: var OrderedTable[A, B], key: A): var B {.deprecated.} =
+  ## retrieves the value at ``t[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  ## Use ```[]``` instead.
+  get(t, key)
 
 proc hasKey*[A, B](t: OrderedTable[A, B], key: A): bool =
   ## returns true iff `key` is in the table `t`.
@@ -679,17 +695,17 @@ iterator mvalues*[A, B](t: OrderedTableRef[A, B]): var B =
   forAllOrderedPairs:
     yield t.data[h].val
 
-proc `[]`*[A, B](t: OrderedTableRef[A, B], key: A): B =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
-  ## default empty value for the type `B` is returned
-  ## and no exception is raised. One can check with ``hasKey`` whether the key
-  ## exists.
+proc `[]`*[A, B](t: OrderedTableRef[A, B], key: A): var B =
+  ## retrieves the value at ``t[key]``. If `key` is not in `t`, the
+  ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
+  ## the key exists.
   result = t[][key]
 
-proc mget*[A, B](t: OrderedTableRef[A, B], key: A): var B =
+proc mget*[A, B](t: OrderedTableRef[A, B], key: A): var B {.deprecated.} =
   ## retrieves the value at ``t[key]``. The value can be modified.
-  ## If `key` is not in `t`, the ``EInvalidKey`` exception is raised.
-  result = t[].mget(key)
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  ## Use ```[]``` instead.
+  result = t[][key]
 
 proc mgetOrPut*[A, B](t: OrderedTableRef[A, B], key: A, val: B): var B =
   ## retrieves value at ``t[key]`` or puts ``val`` if not present, either way
@@ -786,19 +802,31 @@ proc rawGet[A](t: CountTable[A], key: A): int =
     h = nextTry(h, high(t.data))
   result = -1 - h                   # < 0 => MISSING; insert idx = -1 - result
 
-proc `[]`*[A](t: CountTable[A], key: A): int =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
-  ## 0 is returned. One can check with ``hasKey`` whether the key
-  ## exists.
+template get[A](t: CountTable[A], key: A): int {.immediate.} =
   var index = rawGet(t, key)
   if index >= 0: result = t.data[index].val
+  else:
+    when compiles($key):
+      raise newException(KeyError, "key not found: " & $key)
+    else:
+      raise newException(KeyError, "key not found")
 
-proc mget*[A](t: var CountTable[A], key: A): var int =
+proc `[]`*[A](t: CountTable[A], key: A): int =
+  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
+  ## the ``KeyError`` exception is raised. One can check with ``hasKey``
+  ## whether the key exists.
+  get(t, key)
+
+proc `[]`*[A](t: var CountTable[A], key: A): var int =
   ## retrieves the value at ``t[key]``. The value can be modified.
-  ## If `key` is not in `t`, the ``EInvalidKey`` exception is raised.
-  var index = rawGet(t, key)
-  if index >= 0: result = t.data[index].val
-  else: raise newException(KeyError, "key not found: " & $key)
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  get(t, key)
+
+proc mget*[A](t: var CountTable[A], key: A): var int {.deprecated.} =
+  ## retrieves the value at ``t[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  ## Use ```[]``` instead.
+  get(t, key)
 
 proc hasKey*[A](t: CountTable[A], key: A): bool =
   ## returns true iff `key` is in the table `t`.
@@ -927,16 +955,16 @@ iterator mvalues*[A](t: CountTableRef[A]): var int =
   for h in 0..high(t.data):
     if t.data[h].val != 0: yield t.data[h].val
 
-proc `[]`*[A](t: CountTableRef[A], key: A): int =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`,
-  ## 0 is returned. One can check with ``hasKey`` whether the key
-  ## exists.
+proc `[]`*[A](t: CountTableRef[A], key: A): var int =
+  ## retrieves the value at ``t[key]``. The value can be modified.
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
   result = t[][key]
 
-proc mget*[A](t: CountTableRef[A], key: A): var int =
+proc mget*[A](t: CountTableRef[A], key: A): var int {.deprecated.} =
   ## retrieves the value at ``t[key]``. The value can be modified.
-  ## If `key` is not in `t`, the ``EInvalidKey`` exception is raised.
-  result = t[].mget(key)
+  ## If `key` is not in `t`, the ``KeyError`` exception is raised.
+  ## Use ```[]``` instead.
+  result = t[][key]
 
 proc hasKey*[A](t: CountTableRef[A], key: A): bool =
   ## returns true iff `key` is in the table `t`.
diff --git a/lib/pure/strtabs.nim b/lib/pure/strtabs.nim
index 727d5a386..6ed1bb9d8 100644
--- a/lib/pure/strtabs.nim
+++ b/lib/pure/strtabs.nim
@@ -101,21 +101,26 @@ proc rawGet(t: StringTableRef, key: string): int =
     h = nextTry(h, high(t.data))
   result = - 1
 
-proc `[]`*(t: StringTableRef, key: string): string {.rtl, extern: "nstGet".} =
-  ## retrieves the value at ``t[key]``. If `key` is not in `t`, "" is returned
-  ## and no exception is raised. One can check with ``hasKey`` whether the key
-  ## exists.
+template get(t: StringTableRef, key: string): stmt {.immediate.} =
   var index = rawGet(t, key)
   if index >= 0: result = t.data[index].val
-  else: result = ""
+  else:
+    when compiles($key):
+      raise newException(KeyError, "key not found: " & $key)
+    else:
+      raise newException(KeyError, "key not found")
 
-proc mget*(t: StringTableRef, key: string): var string {.
-             rtl, extern: "nstTake".} =
+proc `[]`*(t: StringTableRef, key: string): var string {.
+           rtl, extern: "nstTake".} =
   ## retrieves the location at ``t[key]``. If `key` is not in `t`, the
-  ## ``KeyError`` exception is raised.
-  var index = rawGet(t, key)
-  if index >= 0: result = t.data[index].val
-  else: raise newException(KeyError, "key does not exist: " & key)
+  ## ``KeyError`` exception is raised. One can check with ``hasKey`` whether
+  ## the key exists.
+  get(t, key)
+
+proc mget*(t: StringTableRef, key: string): var string {.deprecated.} =
+  ## retrieves the location at ``t[key]``. If `key` is not in `t`, the
+  ## ``KeyError`` exception is raised. Use ```[]``` instead.
+  get(t, key)
 
 proc hasKey*(t: StringTableRef, key: string): bool {.rtl, extern: "nst$1".} =
   ## returns true iff `key` is in the table `t`.
@@ -227,7 +232,7 @@ proc `$`*(t: StringTableRef): string {.rtl, extern: "nstDollar".} =
     result = "{:}"
   else:
     result = "{"
-    for key, val in pairs(t): 
+    for key, val in pairs(t):
       if result.len > 1: result.add(", ")
       result.add(key)
       result.add(": ")
@@ -239,6 +244,6 @@ when isMainModule:
   assert x["k"] == "v"
   assert x["11"] == "22"
   assert x["565"] == "67"
-  x.mget("11") = "23"
+  x["11"] = "23"
   assert x["11"] == "23"
 
diff --git a/lib/pure/xmltree.nim b/lib/pure/xmltree.nim
index 0bf5b52a4..832cedf47 100644
--- a/lib/pure/xmltree.nim
+++ b/lib/pure/xmltree.nim
@@ -115,11 +115,16 @@ proc `[]`* (n: XmlNode, i: int): XmlNode {.inline.} =
   assert n.k == xnElement
   result = n.s[i]
 
-proc mget* (n: var XmlNode, i: int): var XmlNode {.inline.} =
+proc `[]`* (n: var XmlNode, i: int): var XmlNode {.inline.} =
   ## returns the `i`'th child of `n` so that it can be modified
   assert n.k == xnElement
   result = n.s[i]
 
+proc mget* (n: var XmlNode, i: int): var XmlNode {.inline, deprecated.} =
+  ## returns the `i`'th child of `n` so that it can be modified. Use ```[]```
+  ## instead.
+  n[i]
+
 iterator items*(n: XmlNode): XmlNode {.inline.} =
   ## iterates over any child of `n`.
   assert n.k == xnElement
@@ -128,7 +133,7 @@ iterator items*(n: XmlNode): XmlNode {.inline.} =
 iterator mitems*(n: var XmlNode): var XmlNode {.inline.} =
   ## iterates over any child of `n`.
   assert n.k == xnElement
-  for i in 0 .. n.len-1: yield mget(n, i)
+  for i in 0 .. n.len-1: yield n[i]
 
 proc attrs*(n: XmlNode): XmlAttributes {.inline.} =
   ## gets the attributes belonging to `n`.
diff --git a/lib/system/sets.nim b/lib/system/sets.nim
index 626d43c33..7826fd4b7 100644
--- a/lib/system/sets.nim
+++ b/lib/system/sets.nim
@@ -18,7 +18,7 @@ proc countBits32(n: int32): int {.compilerproc.} =
   v = (v and 0x33333333'i32) +% ((v shr 2'i32) and 0x33333333'i32)
   result = ((v +% (v shr 4'i32) and 0xF0F0F0F'i32) *% 0x1010101'i32) shr 24'i32
 
-proc countBits64(n: int64): int {.compilerproc.} = 
+proc countBits64(n: int64): int {.compilerproc.} =
   result = countBits32(toU32(n and 0xffff'i64)) +
            countBits32(toU32(n shr 16'i64))