Function chegvdx_selected 

pub fn chegvdx_selected(
    ctx: &Context,
    eig_type: EigenType,
    mode: EigenMode,
    fill_mode: FillMode,
    selection: EigenSelection<f32>,
    n: usize,
    a: &mut DeviceMemory<Complex32>,
    lda: usize,
    b: &mut DeviceMemory<Complex32>,
    ldb: usize,
    w: &mut DeviceMemory<f32>,
    workspace: &mut DeviceMemory<Complex32>,
    dev_info: &mut DeviceMemory<i32>,
) -> Result<usize>