MathiasKoch[m]: > <@mathias_koch:matrix.org> Hmm.. Running into a funky `const generics` issue here, that I could use some help with..
> 
> I am attempting to use the crate `bitmaps` (https://crates.io/crates/bitmaps), but are unable to instantiate two maps with different size, as soon as one is generic. 
> Anyone who can help me figure out why, and how to work around?
> 
> ```rust
>     struct Test<const N: usize>
>     where
>         bitmaps::BitsImpl<N>: bitmaps::Bits,
>     {
>         first: bitmaps::Bitmap<N>,
>         second: bitmaps::Bitmap<1>,
>     }
> 
>     impl<const N: usize> Test<N>
>     where
>         bitmaps::BitsImpl<N>: bitmaps::Bits,
>     {
>         fn new() -> Self {
>             Test {
>                 first: bitmaps::Bitmap::new(),
>                 second: bitmaps::Bitmap::new(),
>             }
>         }
>     }
> 
> ```

EDIT: If I change the new fn to
```rust
 impl<const N: usize> Test<N>
    where
        bitmaps::BitsImpl<N>: bitmaps::Bits,
    {
        fn new() -> Self {
            Test {
                first: bitmaps::Bitmap::<N>::new(),
                second: bitmaps::Bitmap::<1>::new(),
            }
        }
    }
```
it works! 🥳