from __future__ import annotations

from dataclasses import dataclass


@dataclass
class VolumeState:
    """Primary dynamic state for rigid adiabatic control volumes."""

    m: float
    U: float

    def as_vector(self) -> list[float]:
        return [self.m, self.U]

    @classmethod
    def from_vector(cls, values: list[float]) -> "VolumeState":
        if len(values) != 2:
            raise ValueError("VolumeState requires exactly two values: [m, U].")
        return cls(m=values[0], U=values[1])