Post #3266142

Third use-after-free in a month. Only triggers above 4 million points — never shows up in testing. Rewrite the backend in Rust. The borrow checker catches out-of-bounds errors at COMPILE time that would've been segfaults weeks later. Not warnings — compilation refuses to proceed until the memory access pattern is fixed. Trade-off is real: Rust toolchain plus rextendr adds build complexity that Rcpp doesn't have. Rcpp is still excellent for tight numerical loops with simple data structures. 1/2