Enum SqpStatus 

pub enum SqpStatus {
    Optimal,
    MaxIter,
    InfeasibleSubproblem,
    LineSearchFailed,
    QpStepFailed,
    QpIterationLimit,
    Unbounded,
}

Variants

Optimal

KKT residuals all below their tolerances.

MaxIter

max_iter reached without convergence.

InfeasibleSubproblem

QP subproblem returned an Infeasible status (elastic mode certified the QP infeasible).

LineSearchFailed

Line search failed to find an acceptable step (Phase 5b commit 5+; not produced by the c3 always-full-step loop).

QpStepFailed

The QP subproblem solver neither produced a usable step nor certified infeasibility — it hit its own iteration limit or a numerical breakdown (e.g. the extreme m/n ≫ 1 degenerate phase-1 of #282). This is an HONEST non-committal failure: the SQP could not compute a search direction, but — unlike InfeasibleSubproblem — it makes no infeasibility claim it cannot back with a certificate. Maps to Search_Direction_Becomes_Too_Small.

QpIterationLimit

The QP subproblem exhausted its own iteration budget ([QpOptions::max_iter], the sqp_qp_max_iter option) without converging or certifying anything.

Split out from QpStepFailed because the two call for opposite remedies and the merged status actively misled. A budget exhaustion is actionable — raise the limit — whereas Search_Direction_Becomes_Too_Small reads as a numerical stall with nothing to turn. On the Maros-Mészáros set the merged mapping hid the single largest failure class: the cold-start active-set method needs roughly one iteration per active-set change, so the flat default of 200 is below what a few hundred constraints require, and dozens of problems reported a step-size failure when they had simply run out of budget. DUALC1 (n=9, m=215) is the type case — it exits here at the default and solves exactly, in one outer iteration, at a larger limit.

Maps to Maximum_Iterations_Exceeded.

Unbounded

The problem is unbounded below: the step QP returned a certified recession ray (zero curvature, feasible for every step length, strict descent) and that ray was re-verified against the true NLP — feasible points along it drive f toward −∞ at (at least) half the linear rate out to 1e12·‖d‖. Maps to Diverging_Iterates, POUNCE’s (Ipopt’s) unboundedness verdict, the same status the IPM paths report on an unbounded model (gh #388). An unverified unbounded step QP is a statement about the local model only and falls back to QpStepFailed.

Trait Implementations

impl Clone for SqpStatus

fn clone(&self) -> SqpStatus

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Copy for SqpStatus

impl Debug for SqpStatus

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Display for SqpStatus

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for SqpStatus

impl PartialEq for SqpStatus

fn eq(&self, other: &SqpStatus) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for SqpStatus