Function csr2csc_ex2_buffer_size 

pub fn csr2csc_ex2_buffer_size<T: SparseScalar + DeviceRepr>(
    handle: &Handle,
    m: i32,
    n: i32,
    nnz: i32,
    csr_val: &DeviceBuffer<T>,
    csr_row_ptr: &DeviceBuffer<i32>,
    csr_col_ind: &DeviceBuffer<i32>,
    csc_val: &mut DeviceBuffer<T>,
    csc_col_ptr: &mut DeviceBuffer<i32>,
    csc_row_ind: &mut DeviceBuffer<i32>,
    copy_values: bool,
    idx_base: IndexBase,
    alg: Csr2CscAlg,
) -> Result<usize>

Workspace size in bytes for csr2csc_ex2.