Function blosc2_getitem 

pub unsafe extern "C" fn blosc2_getitem(
    src: *const c_void,
    srcsize: i32,
    start: c_int,
    nitems: c_int,
    dest: *mut c_void,
    destsize: i32,
) -> c_int

@brief Get @p nitems (of @p typesize size) in @p src buffer starting in @p start. The items are returned in @p dest buffer. The dest buffer should have enough space for storing all items. This function is a more secure version of #blosc1_getitem.

@param src The compressed buffer holding the data to be retrieved. @param srcsize Size of the compressed buffer. @param start The position of the first item (of @p typesize size) from where data will be retrieved. @param nitems The number of items (of @p typesize size) that will be retrieved. @param dest The buffer where the retrieved data will be stored decompressed. @param destsize Size of the buffer where retrieved data will be stored.

@return The number of bytes copied to @p dest or a negative value if some error happens.