Function create_fastcover_dict_from_slice 

pub fn create_fastcover_dict_from_slice<W: Write>(
    sample: &[u8],
    output: &mut W,
    dict_size: usize,
    fastcover: &FastCoverOptions,
    finalize: FinalizeOptions,
) -> Result<FastCoverTuned>

Available on crate feature dict-builder only.

Train and finalize a FastCOVER dictionary from a corpus already in memory.

The same work as create_fastcover_dict_from_source for a caller that holds the bytes: the corpus is the largest allocation training makes, and handing it over as a slice keeps it to one copy rather than buffering it a second time inside.