wording: source range may not get popped

Author: ntrel

std/range/package.d

@@ -3884,7 +3884,7 @@ pure @safe nothrow @nogc unittest
     `drop` is a convenience function which calls
     $(REF popFrontN, std, range, primitives)`(range, n)` and returns `range`.
     Unlike `popFrontN`, the range argument is not passed by `ref`, so
-    it may not be mutated.
+    the source range may not get popped.
 
     `drop` makes it easier to pop elements from a range rvalue
     and then pass it to another function within a single expression,
@@ -4039,7 +4039,7 @@ if (isBidirectionalRange!R)
     `dropOne` is a convenience function which calls
     `range.popFront()` and returns `range`.
     Unlike `popFront`, the range argument is not passed by `ref`, so
-    it may not be mutated.
+    the source range may not get popped.
 
     `dropOne` makes it easier to pop an element from a range rvalue
     and then pass it to another function within a single expression,