Function gsl_sys::gsl_linalg_cholesky_band_solve

pub unsafe extern "C" fn gsl_linalg_cholesky_band_solve(
    LLT: *const gsl_matrix, 
    b: *const gsl_vector, 
    x: *mut gsl_vector
) -> c_int

This is supported on crate feature v2_6 only.