Struct BookedCostInvariantError 

pub struct BookedCostInvariantError {
    pub per_unit: Decimal,
    pub total: Decimal,
    pub units: Decimal,
    pub derived_total: Decimal,
    pub abs_diff: Decimal,
    pub tolerance: Option<Decimal>,
    pub overflow: bool,
}

Diagnostic for a failed BookedCost consistency check.

Returned by BookedCost::try_new in three cases:

• Mismatch: per_unit * |units| doesn’t agree with total to within the rust_decimal rounding floor.
• Zero units: every per_unit “works” by zero-multiplication so the invariant carries no information; the post-booking shape is structurally meaningless without units.
• Overflow: per_unit * |units| would exceed Decimal::MAX (~7.92e28). Both operands fit in Decimal individually but their product doesn’t. A wire client can reach this with extreme inputs; surfacing it as a typed error keeps the host from panicking on multiplication.

Carries the inputs and (for the mismatch case) the computed residual so trust-boundary callers can surface a meaningful error to the originating plugin or wire client (“you sent per_unit=50, total=999 with units=10; derived total would be 500, off by 499 — far outside tolerance 1e-20”). Mapping this to a ConversionError variant gives plugin authors a typed category for the failure instead of conflating with InvalidNumber (parse failure).

Fields

per_unit: Decimal

The per-unit value the caller supplied.

total: Decimal

The total value the caller supplied.

units: Decimal

The units value the caller supplied (caller-side sign retained so error messages can show what came in).

derived_total: Decimal

per_unit * |units|, the value we’d expect total to equal. Decimal::ZERO when the multiplication couldn’t be performed (zero units, or overflow — see Self::overflow).

abs_diff: Decimal

|derived_total - total|, the magnitude of the violation. Decimal::ZERO for the zero-units and overflow cases.

tolerance: Option<Decimal>

The tolerance threshold we tested against. None when units was zero or the multiplication overflowed — see Self::overflow to distinguish the two.

overflow: bool

true when per_unit * |units| overflowed Decimal::MAX (~7.92e28). Distinguishes the overflow case from the zero-units case, since both leave tolerance: None.

Trait Implementations

impl Clone for BookedCostInvariantError

fn clone(&self) -> BookedCostInvariantError

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for BookedCostInvariantError

impl Debug for BookedCostInvariantError

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

Formats the value using the given formatter.

impl Display for BookedCostInvariantError

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

Formats the value using the given formatter.

impl Eq for BookedCostInvariantError

impl Error for BookedCostInvariantError

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 BookedCostInvariantError

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

Tests for self and other values to be equal, and is used by ==.

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

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl StructuralPartialEq for BookedCostInvariantError