Struct arrayfire::Indexer

pub struct Indexer<'object> { /* fields omitted */ }

Struct to manage an array of resources of type af_indexer_t(ArrayFire C struct)

Examples

Given below are examples illustrating correct and incorrect usage of Indexer struct.

Correct Usage

use arrayfire::{Array, Dim4, randu, index_gen, Indexer};

// Always be aware of the fact that, the `Seq` or `Array` objects
// that we intend to use for indexing via `Indexer` have to outlive
// the `Indexer` object created in this context.

let dims    = Dim4::new(&[1, 3, 1, 1]);
let indices = [1u8, 0, 1];
let idx     = Array::new(&indices, dims);
let values  = [2.0f32, 5.0, 6.0];
let arr     = Array::new(&values, dims);

let mut idxr = Indexer::new();

// `idx` is created much before idxr, thus will
// stay in scope at least as long as idxr
idxr.set_index(&idx, 0, None);

index_gen(&arr, idxr);

Incorrect Usage

// Say, you create an Array on the fly and try
// to call set_index, it will throw the given below
// error or something similar to that
idxr.set_index(&Array::new(&[1, 0, 1], dims), 0, None);

error: borrowed value does not live long enough
  --> <anon>:16:55
  |
16 | idxr.set_index(&Array::new(&[1, 0, 1], dims), 0, None);
  |                 ----------------------------          ^ temporary value dropped here while still borrowed
  |                 |
  |                 temporary value created here
...
19 | }
  | - temporary value needs to live until here
  |
  = note: consider using a `let` binding to increase its lifetime

Methods

impl<'object> Indexer<'object>

pub fn new() -> Self

Create a new Indexer object and set the dimension specific index objects later

pub fn set_index<'s, T>(
    &'s mut self,
    idx: &'object T,
    dim: u32,
    is_batch: Option<bool>
) where
    T: Indexable + 'object, 

Set either Array or Seq to index an Array along idx dimension

pub fn len(&self) -> usize

Get number of indexing objects set

pub fn get(&self) -> i64

Get native(ArrayFire) resource handle

Trait Implementations

impl<'object> Drop for Indexer<'object>

fn drop(&mut self)

Executes the destructor for this type.