Checks if the cursor may have additional results

# MongoDB\Driver\Cursor::isDead

(mongodb >=1.0.0)

MongoDB\Driver\Cursor::isDead — Checks if the cursor may have additional results

### 説明

final public MongoDB\Driver\Cursor::isDead ( void ) : bool

Checks whether the cursor may have additional results available to read. A cursor is initially "alive" but may become "dead" for any of the following reasons:

- Advancing a non-tailable cursor did not return a document
- The cursor encountered an error
- The cursor read its last batch to completion
- The cursor reached its configured limit

This is primarily useful with tailable cursors.

### パラメータ

この関数にはパラメータはありません。

### 返り値

Returns `TRUE` if additional results are not available, and `FALSE` otherwise.

### エラー / 例外

- 引数のパースに失敗した場合に MongoDB\Driver\Exception\InvalidArgumentException をスローします。

### 例

例1 MongoDB\Driver\Cursor::isDead() example

`<?php
$manager = new MongoDB\Driver\Manager("mongodb://localhost:27017");
$query = new MongoDB\Driver\Query([]);
$bulk = new MongoDB\Driver\BulkWrite;
$bulk->insert(['x' => 1]);
$bulk->insert(['x' => 2]);
$bulk->insert(['x' => 3]);
$manager->executeBulkWrite('db.collection', $bulk);
$cursor = $manager->executeQuery('db.collection', $query);
$iterator = new IteratorIterator($cursor);
$iterator->rewind();
var_dump($cursor->isDead());
$iterator->next();
var_dump($cursor->isDead());
$iterator->next();
var_dump($cursor->isDead());
$iterator->next();
var_dump($cursor->isDead());
?>`

上の例の出力は以下となります。

    bool(false)
    bool(false)
    bool(false)
    bool(true)