And of course the kernel - which doesn't even use Rust's Vec but has its own entire allocator library because it is the kernel - likewise provides https://rust

And of course the kernel - which doesn't even use Rust's Vec but has its own entire allocator library because it is the kernel - likewise provides https://rust.docs.kernel.org/next/kernel/alloc/kvec/struct.Vec.html#method.push_within_capacity https://rust.docs.kernel.org/next/kernel/alloc/kvec/struct.V... Vec::push_within_capacity is a nice API to confront the reality of running out of memory. "Clever" ideas that don't actually work are obviously ineffective once we see this API. We need to do something with this T, we can't just say "Somebody else should ensure I have room to store it" because it's too late now. Here's your T back, there was no more space.