This crate zeros all memory before freeing it, so if you keep secrets on the heap, you can be sure they no longer exist once they are freed.
#[global_allocator]
static ALLOC: zeroize_alloc::ZeroizingAlloc<YourAllocator> = ZeroizingAlloc(YourAllocator);
If you want to use the default allocator, use std::alloc::System
.