Look at vectors or hash maps. This is a perfect example of the Rust philosophy. Namely, writing complex low-level abstractions that offer a convenient and reliable high-level API.
It uses unsafe, but few people understand what it really is. Rust has clear invariants (for example, that a pointer to T always points to an existing and valid T) that are enforced by the compiler. Using unsafe code is shifting the enforcement of these invariants from the compiler to the programmer. The advantage compared to C is that unsafe code is limited to undefined blocks that are easy to test.
The data structure you describe should be done exactly this way. And it is not a task for the average programmer.
It uses unsafe, but few people understand what it really is. Rust has clear invariants (for example, that a pointer to T always points to an existing and valid T) that are enforced by the compiler. Using unsafe code is shifting the enforcement of these invariants from the compiler to the programmer. The advantage compared to C is that unsafe code is limited to undefined blocks that are easy to test.
The data structure you describe should be done exactly this way. And it is not a task for the average programmer.