I wrote a small function to return the Sha512 of a file's content. I auto-completed the function's return type and got this:

use sha2::{Digest, Sha512};
pub fn sha512_for<P: AsRef<Path>>(
    path_in: P,
) -> Result<
    sha2::digest::generic_array::GenericArray<
        u8,
        sha2::digest::typenum::UInt<
            sha2::digest::typenum::UInt<
                sha2::digest::typenum::UInt<
                    sha2::digest::typenum::UInt<
                        sha2::digest::typenum::UInt<
                            sha2::digest::typenum::UInt<
                                sha2::digest::typenum::UInt<
                                    sha2::digest::typenum::UTerm,
                                    sha2::digest::consts::B1,
                                >,
                                sha2::digest::consts::B0,
                            >,
                            sha2::digest::consts::B0,
                        >,
                        sha2::digest::consts::B0,
                    >,
                    sha2::digest::consts::B0,
                >,
                sha2::digest::consts::B0,
            >,
            sha2::digest::consts::B0,
        >,
    >,
    std::io::Error,
> {
    let mut hasher = Sha512::new();
    let file_content = std::fs::read(path_in)?;
    hasher.update(file_content);
    Ok(hasher.finalize())
}

In my short rust programming experience I had never seen such a beast. The return type is longer than the function body!
I'm wondering: how am I supposed to write such a type signature myself?
Am I missing something that make this more manageable ?

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