Function rustc_mir::const_eval::eval_queries::op_to_const

pub(in const_eval) fn op_to_const<'tcx>(
    ecx: &InterpCx<'_, 'tcx, CompileTimeInterpreter<'_, 'tcx>>, 
    op: OpTy<'tcx>
) -> ConstValue<'tcx>

This function converts an interpreter value into a constant that is meant for use in the type system.