This isn't a "leak": a leak is a leak, and this isn't a leak... this is just something Valgrind is reporting because it could be a leak due to exhibiting a pattern indistinguishable from something that actually was leaked from the perspective of a tool that only is able to work from a dynamically maintained list of heap allocations and the event "program has now terminated". Saying this is a leak is somewhat equivalent to claiming that because the executable code itself wasn't deallocated by the program before it exited the code was "leaked": it just so happens that as an implementation detail this data structure is lazily dynamically allocated, but it should be considered a static part of the program. In a world where things Valgrind reported were "leaks" as opposed to simply "outstanding heap allocations" then I'd be happier claiming this was a bug in Valgrind than claiming that this feature of the language standard should have the word "leak" used to describe it ;P.