Enum Error 

#[non_exhaustive]
pub enum Error {
    InvalidProblem(String),
    ArtificialVariablesRequired,
    NotDualFeasible(String),
    NotOptimal,
    IterationLimit(usize),
}

Errors returned by solve and reoptimize.

Infeasible and unbounded problems are not errors: they are reported through Status.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

InvalidProblem(String)

The problem is malformed (e.g. a constraint with the wrong number of coefficients).

ArtificialVariablesRequired

Method::Simplex was requested but the problem has >= or = constraints, which need artificial variables. Use BigM or TwoPhase.

NotDualFeasible(String)

Method::DualSimplex was requested but the slack basis is not dual feasible (a cost with the wrong sign, or an equality constraint), so the dual simplex cannot start. Use BigM or TwoPhase.

NotOptimal

reoptimize was given a previous solution that is not optimal, so there is no basis to start from. Solve the extended problem from scratch instead.

IterationLimit(usize)

The iteration limit in Options was reached (possible cycling).

Trait Implementations

impl Clone for Error

fn clone(&self) -> Self

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for Error

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

Formats the value using the given formatter.

impl Display for Error

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

Formats the value using the given formatter.

impl Eq for Error

impl Error for Error

fn source(&self) -> Option<&(dyn Error + 'static)>

Returns the lower-level source of this error, if any.

fn description(&self) -> &str

👎Deprecated since 1.42.0:

use the Display impl or to_string()

fn cause(&self) -> Option<&dyn Error>

👎Deprecated since 1.33.0:

replaced by Error::source, which can support downcasting

fn provide<'a>(&'a self, request: &mut Request<'a>)

🔬This is a nightly-only experimental API. (error_generic_member_access)

Provides type-based access to context intended for error reports.

impl PartialEq for Error

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

Equality operator ==.

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

Inequality operator !=.

impl StructuralPartialEq for Error