pub unsafe trait TransmuteFrom<Src, const ASSUME: Assume = { Assume::NOTHING }>
where
    Src: ?Sized,
{
    unsafe fn transmute(src: Src) -> Self
    where
        Src: Sized,
        Self: Sized,
    {
        ...
    }
}

#[derive(PartialEq, Eq, Clone, Copy, Debug)]
pub struct Assume {
    pub alignment: bool,
    pub lifetimes: bool,
    pub safety: bool,
    pub validity: bool,
}

impl Assume {
    pub const NOTHING: Self =
        Self { alignment: false, lifetimes: false, safety: false, validity: false };

    pub const ALIGNMENT: Self = Self { alignment: true, ..Self::NOTHING };
    pub const LIFETIMES: Self = Self { lifetimes: true, ..Self::NOTHING };
    pub const SAFETY: Self = Self { safety: true, ..Self::NOTHING };
    pub const VALIDITY: Self = Self { validity: true, ..Self::NOTHING };

    pub const fn and(self, other_assumptions: Self) -> Self { ... }
    pub const fn but_not(self, other_assumptions: Self) -> Self { ... }
}