Method mut_vec

src/fast.rs:114–120

Accesses the [`FastVec`] mutably as a [`Vec`]. # Safety If `f` panics the [`Vec`] must be unmodified.

(&mut self, f: impl FnOnce(&mut Vec<T>))

    /// # Safety
    /// If `f` panics the [`Vec`] must be unmodified.
    unsafe fn mut_vec(&mut self, f: impl FnOnce(&mut Vec<T>)) {
        let copied = std::ptr::read(self as *mut FastVec<T>);
        let mut vec = ManuallyDrop::new(Vec::from(copied));
        f(&mut vec);
        let copied = FastVec::from(ManuallyDrop::into_inner(vec));
        std::ptr::write(self as *mut FastVec<T>, copied);
    }

    /// Get a pointer to write to without incrementing length.
    #[inline(always)]