Trait ConstantExt

pub trait ConstantExt<'tcx>: Sized + Debug {
    // Required method
    fn eval_constant<S: UnderOwnerState<'tcx>>(&self, s: &S) -> Option<Self>;

    // Provided method
    fn translate_uneval(
        &self,
        s: &impl UnderOwnerState<'tcx>,
        ucv: UnevaluatedConst<'tcx>,
        span: Span,
    ) -> TranslateUnevalRes<Self> { ... }
}

Required Methods

fn eval_constant<S: UnderOwnerState<'tcx>>(&self, s: &S) -> Option<Self>

Provided Methods

fn translate_uneval( &self, s: &impl UnderOwnerState<'tcx>, ucv: UnevaluatedConst<'tcx>, span: Span, ) -> TranslateUnevalRes<Self>

Performs a one-step translation of a constant.

• When a constant refers to a named top-level constant, we want to use that, thus we translate the constant to a ConstantExprKind::GlobalName. This is captured by the variant TranslateUnevalRes::GlobalName.
• When a constant refers to a anonymous top-level constant, we evaluate it. If the evaluation fails, we report an error: we expect every AnonConst to be reducible. Otherwise, we return the variant TranslateUnevalRes::EvaluatedConstant.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl<'tcx> ConstantExt<'tcx> for Const<'tcx>

fn eval_constant<S: UnderOwnerState<'tcx>>(&self, s: &S) -> Option<Self>

impl<'tcx> ConstantExt<'tcx> for Const<'tcx>

fn eval_constant<S: UnderOwnerState<'tcx>>(&self, s: &S) -> Option<Self>

Implementors