Function secp256k1_sys::secp256k1_xonly_pubkey_from_pubkey

pub unsafe extern "C" fn secp256k1_xonly_pubkey_from_pubkey(
    cx: *const Context, 
    xonly_pubkey: *mut XOnlyPublicKey, 
    pk_parity: *mut c_int, 
    pubkey: *const PublicKey
) -> c_int