Function gsl_sys::gsl_bst_trav_find

pub unsafe extern "C" fn gsl_bst_trav_find(
    item: *const c_void, 
    trav: *mut gsl_bst_trav, 
    w: *const gsl_bst_workspace
) -> *mut c_void

This is supported on crate feature v2_6 only.