In Rust, memory leaks are considered "safe"; you don't need unsafe to create a memory leak. There's even a function in the standard library (std::mem::forget) t

In Rust, memory leaks are considered "safe"; you don't need unsafe to create a memory leak. There's even a function in the standard library (std::mem::forget) to explicitly leak a value, and it's not marked as unsafe. And even without that function, it's very easy to leak memory in safe code (just create a cycle with reference-counted values). But yes, memory managers generally require unsafe. Consider what happens when you release memory containing a value of type A, and that memory is later allocated for a value of type B. This is equivalent to a transmute between types A and B, which requires unsafe.