@ is a sigil-like operator

tests/run/toprprec.nim

@@ -4,6 +4,22 @@ discard """
 """
 # Test operator precedence: 
 
+template `@` (x: expr): expr {.immediate.} = self.x
+template `@!` (x: expr): expr {.immediate.} = x
+template `===` (x: expr): expr {.immediate.} = x
+
+type
+  TO = object
+    x: int
+  TA = tuple[a, b: int, obj: TO]
+  
+proc init(self: var TA): string =
+  @a = 3
+  === @b = 4
+  @obj.x = 4
+  @! === result = "abc"
+  result = @b.`$`
+
 assert 3+5*5-2 == 28- -26-28
 
 proc `^-` (x, y: int): int =  
@@ -12,6 +28,11 @@ proc `^-` (x, y: int): int =
   
 assert 34 ^- 6 ^- 2 == 30
 assert 34 - 6 - 2 == 26
+
+
+var s: TA
+assert init(s) == "4"
+
 echo "done"