Function IpoptEnableIterHistory 

#[unsafe(no_mangle)]
pub unsafe extern "C" fn IpoptEnableIterHistory(
    ipopt_problem: IpoptProblem,
) -> Bool

Enable per-iteration history capture on the underlying IpoptApplication. Must be called before IpoptSolve for the trajectory to appear in the report written by IpoptWriteSolveReport. Off by default — capturing each iterate has a small per-iter cost the IPM core skips otherwise.

Returns TRUE on success, FALSE if ipopt_problem is NULL.

Safety

ipopt_problem must be a valid handle returned by CreateIpoptProblem (or NULL).