This is because delete is an operator that can be overridden, and whether it has been overridden isn't known until link time. void operator delete(void*) {

This is because delete is an operator that can be overridden, and whether it has been overridden isn't known until link time. void operator delete(void*) { } int main() { int on_stack; int& ref = on_stack; int* ptr = &ref; delete ptr; return 0; } and now it's safe :P... and yes, never freeing any memory is arguably a perfectly valid memory management strategy. Ok, this example is nuts... but it's a feature of C++, in the C tradition, that it lets you do crazy things. Can I plug custom per-type memory allocators in to Rust?