ices/108329.rs: fixed with errors

[github-actions]

Issue: rust-lang/rust#108329

#![feature(generic_const_exprs)]
#![allow(incomplete_features)]

pub enum Restriction<const V: bool = true> {}
pub trait Valid {}

impl Valid for Restriction<true> {}

/**
    a circular buffer
*/
pub struct CircularBuffer<T, const S: usize> {
    buffer: Vec<T>,
    index: usize,
}

impl<T, const S: usize> CircularBuffer<T, { S }>
where
    Restriction<{ S > 0 }>: Valid,
{
    /**
        create a new [`CircularBuffer`] instance
    */
    pub fn new() -> Self {
        Self {
            buffer: Vec::with_capacity(S),
            index: S - 1,
        }
    }

    /**
        push a value onto the buffer
    */
    pub fn push(&mut self, value: T) {
        self.index = self.index.checked_add(1).unwrap_or(0) % S;
        match self.count() < self.capacity() {
            true => self.buffer.insert(self.index, value),
            false => self.buffer[self.index] = value,
        }
    }

    /**
        push a value onto the buffer
    */
    pub fn pop(&mut self) -> Result<T, CircularBufferError> {
        if self.count() == 0 {
            Err(CircularBufferError::Underflow)?
        }

        let old = self.buffer.remove(self.index);
        self.index = self.index.checked_sub(1).unwrap_or(S - 1);
        Ok(old)
    }
}

impl<T, const S: usize> CircularBuffer<T, { S }> {
    /**
        returns the current count of the buffer
    */
    pub fn count(&self) -> usize {
        self.buffer.len()
    }

    /**
        returns the max capacity of the buffer
    */
    pub const fn capacity(&self) -> usize {
        S
    }
}

impl<T, const S: usize> CircularBuffer<T, { S }>
where
    T: Clone,
{
    /**
        take the values in a vec, leaving an empty buffer
    */
    pub fn take(&mut self) -> Vec<T> {
        let mut buf = Vec::with_capacity(self.buffer.len());
        buf.copy_from_slice(self.buffer[..]);
        self.index = S - 1;
        buf
    }

    /**
        returns true if the buffer is empty
    */
    pub fn is_empty(&self) -> bool {
        self.buffer.is_empty()
    }
}

#[derive(Debug, PartialEq)]
pub enum CircularBufferError {
    /// attempted to pop when buffer is empty
    Underflow,
}

fn main() {}

=== stdout ===
=== stderr ===
error[E0308]: mismatched types
  --> /home/runner/work/glacier/glacier/ices/108329.rs:81:29
   |
81 |         buf.copy_from_slice(self.buffer[..]);
   |             --------------- ^^^^^^^^^^^^^^^
   |             |               |
   |             |               expected `&[_]`, found `[T]`
   |             |               help: consider borrowing here: `&self.buffer[..]`
   |             arguments to this method are incorrect
   |             here the type of `buf` is inferred to be `[_]`
   |
   = note: expected reference `&[_]`
                  found slice `[T]`
note: method defined here
  --> /rustc/44cfafe2fafe816395d3acc434663a45d5178c41/library/core/src/slice/mod.rs:3325:12

error[E0277]: the trait bound `T: Copy` is not satisfied
  --> /home/runner/work/glacier/glacier/ices/108329.rs:81:13
   |
81 |         buf.copy_from_slice(self.buffer[..]);
   |             ^^^^^^^^^^^^^^^ the trait `Copy` is not implemented for `T`
   |
note: required by a bound in `core::slice::<impl [T]>::copy_from_slice`
  --> /rustc/44cfafe2fafe816395d3acc434663a45d5178c41/library/core/src/slice/mod.rs:3325:5
help: consider further restricting this bound
   |
74 |     T: Clone + std::marker::Copy,
   |              +++++++++++++++++++

error: aborting due to 2 previous errors

Some errors have detailed explanations: E0277, E0308.
For more information about an error, try `rustc --explain E0277`.
==============