diff --git a/src/Set.php b/src/Set.php
index f9d6d0f..2aded22 100644
--- a/src/Set.php
+++ b/src/Set.php
@@ -44,6 +44,35 @@ public static function distinct(iterable $data, bool $strict = true): \Generator
         }
     }
 
+    /**
+     * Iterate only the distinct elements using $compareBy function for getting comparable value.
+     *
+     * Supports only strict-type comparisons:
+     *  - scalars: compares strictly by type
+     *  - objects: always treats different instances as not equal to each other
+     *  - arrays: compares serialized
+     *
+     * @template T
+     *
+     * @param iterable<T> $data
+     * @param callable $compareBy
+     *
+     * @return \Generator<T>
+     */
+    public static function distinctBy(iterable $data, callable $compareBy): \Generator
+    {
+        $map = [];
+
+        foreach ($data as $datum) {
+            $hash = UniqueExtractor::getString($compareBy($datum), true);
+
+            if (!isset($map[$hash])) {
+                $map[$hash] = true;
+                yield $datum;
+            }
+        }
+    }
+
     /**
      * Iterates the intersection of iterables in strict type mode.
      *
diff --git a/src/Stream.php b/src/Stream.php
index c8682c6..7469112 100644
--- a/src/Stream.php
+++ b/src/Stream.php
@@ -695,6 +695,28 @@ public function distinct(bool $strict = true): self
         return $this;
     }
 
+    /**
+     * Filter out elements from the iterable source only returning unique elements.
+     *
+     * Using $compareBy function for getting comparable value.
+     *
+     * Supports only strict-type comparisons:
+     *  - scalars: compares strictly by type
+     *  - objects: always treats different instances as not equal to each other
+     *  - arrays: compares serialized
+     *
+     * @param callable $compareBy
+     *
+     * @return $this
+     *
+     * @see Single::distinctBy()
+     */
+    public function distinctBy(callable $compareBy): self
+    {
+        $this->iterable = Set::distinctBy($this->iterable, $compareBy);
+        return $this;
+    }
+
     /**
      * Cycle through the elements of iterable source sequentially forever
      *
diff --git a/tests/Set/DistinctByTest.php b/tests/Set/DistinctByTest.php
new file mode 100644
index 0000000..a1fc95d
--- /dev/null
+++ b/tests/Set/DistinctByTest.php
@@ -0,0 +1,659 @@
+<?php
+
+declare(strict_types=1);
+
+namespace IterTools\Tests\Set;
+
+use IterTools\Set;
+use IterTools\Tests\Fixture\ArrayIteratorFixture;
+use IterTools\Tests\Fixture\GeneratorFixture;
+use IterTools\Tests\Fixture\IteratorAggregateFixture;
+
+class DistinctByTest extends \PHPUnit\Framework\TestCase
+{
+    /**
+     * @dataProvider dataProviderForArray
+     * @param        array $data
+     * @param        callable $compareBy
+     * @param        array $expected
+     */
+    public function testArray(array $data, callable $compareBy, array $expected): void
+    {
+        // Given
+        $result = [];
+
+        // When
+        foreach (Set::distinctBy($data, $compareBy) as $datum) {
+            $result[] = $datum;
+        }
+
+        // Then
+        $this->assertEquals($expected, $result);
+    }
+
+    public function dataProviderForArray(): array
+    {
+        return [
+            [
+                [],
+                fn ($item) => $item,
+                [],
+            ],
+            [
+                [],
+                fn ($item) => $item['name'],
+                [],
+            ],
+            [
+                [1],
+                fn ($item) => $item,
+                [1],
+            ],
+            [
+                [1, 1],
+                fn ($item) => $item,
+                [1],
+            ],
+            [
+                [1, '1'],
+                fn ($item) => $item,
+                [1, '1'],
+            ],
+            [
+                ['1', 1],
+                fn ($item) => $item,
+                ['1', 1],
+            ],
+            [
+                ['aa', 'bb', 'aa'],
+                fn ($item) => $item,
+                ['aa', 'bb'],
+            ],
+            [
+                [1, 2, 1, 2, 3],
+                fn ($item) => $item,
+                [1, 2, 3],
+            ],
+            [
+                ['1', 2, '1', '2', 3],
+                fn ($item) => $item,
+                ['1', 2, '2', 3],
+            ],
+            [
+                ['1', 2, '1', '2', 3],
+                fn ($item) => (int)$item,
+                ['1', 2, '3'],
+            ],
+            [
+                [[1], [1], [1, 2]],
+                fn ($item) => $item,
+                [[1], [1, 2]],
+            ],
+            [
+                [[1], [1], [1, 2]],
+                fn ($item) => $item[0],
+                [[1]],
+            ],
+            [
+                [[1], 'a' => [1]],
+                fn ($item) => $item,
+                [[1]],
+            ],
+            [
+                [false, null, 0, 0.0, ''],
+                fn ($item) => $item,
+                [false, null, 0, 0.0, ''],
+            ],
+            [
+                [true, 1, '1', 1.0, '1.0'],
+                fn ($item) => $item,
+                [true, 1, '1', 1.0, '1.0'],
+            ],
+            [
+                [['a' => 1, 'b' => 2], ['a' => 1], ['a' => 1], 2, 2],
+                fn ($item) => $item,
+                [['a' => 1, 'b' => 2], ['a' => 1], 2],
+            ],
+            [
+                [['a' => 1, 'b' => 2], ['a' => 1], ['a' => 1], ['a' => 2]],
+                fn ($item) => $item['a'],
+                [['a' => 1, 'b' => 2], ['a' => 2]],
+            ],
+            [
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+                fn ($item) => $item,
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+            [
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+                fn ($item) => $item['id'],
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+            [
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+                fn ($item) => $item['name'],
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * @dataProvider dataProviderForGenerators
+     * @param        \Generator $data
+     * @param        callable $compareBy
+     * @param        array $expected
+     */
+    public function testGenerators(\Generator $data, callable $compareBy, array $expected): void
+    {
+        // Given
+        $result = [];
+
+        // When
+        foreach (Set::distinctBy($data, $compareBy) as $datum) {
+            $result[] = $datum;
+        }
+
+        // Then
+        $this->assertEquals($expected, $result);
+    }
+
+    public function dataProviderForGenerators(): array
+    {
+        $gen = fn ($data) => GeneratorFixture::getGenerator($data);
+
+        return [
+            [
+                $gen([]),
+                fn ($item) => $item,
+                [],
+            ],
+            [
+                $gen([]),
+                fn ($item) => $item['name'],
+                [],
+            ],
+            [
+                $gen([1]),
+                fn ($item) => $item,
+                [1],
+            ],
+            [
+                $gen([1, 1]),
+                fn ($item) => $item,
+                [1],
+            ],
+            [
+                $gen([1, '1']),
+                fn ($item) => $item,
+                [1, '1'],
+            ],
+            [
+                $gen(['1', 1]),
+                fn ($item) => $item,
+                ['1', 1],
+            ],
+            [
+                $gen(['aa', 'bb', 'aa']),
+                fn ($item) => $item,
+                ['aa', 'bb'],
+            ],
+            [
+                $gen([1, 2, 1, 2, 3]),
+                fn ($item) => $item,
+                [1, 2, 3],
+            ],
+            [
+                $gen(['1', 2, '1', '2', 3]),
+                fn ($item) => $item,
+                ['1', 2, '2', 3],
+            ],
+            [
+                $gen(['1', 2, '1', '2', 3]),
+                fn ($item) => (int)$item,
+                ['1', 2, '3'],
+            ],
+            [
+                $gen([[1], [1], [1, 2]]),
+                fn ($item) => $item,
+                [[1], [1, 2]],
+            ],
+            [
+                $gen([[1], [1], [1, 2]]),
+                fn ($item) => $item[0],
+                [[1]],
+            ],
+            [
+                $gen([[1], 'a' => [1]]),
+                fn ($item) => $item,
+                [[1]],
+            ],
+            [
+                $gen([false, null, 0, 0.0, '']),
+                fn ($item) => $item,
+                [false, null, 0, 0.0, ''],
+            ],
+            [
+                $gen([true, 1, '1', 1.0, '1.0']),
+                fn ($item) => $item,
+                [true, 1, '1', 1.0, '1.0'],
+            ],
+            [
+                $gen([['a' => 1, 'b' => 2], ['a' => 1], ['a' => 1], 2, 2]),
+                fn ($item) => $item,
+                [['a' => 1, 'b' => 2], ['a' => 1], 2],
+            ],
+            [
+                $gen([['a' => 1, 'b' => 2], ['a' => 1], ['a' => 1], ['a' => 2]]),
+                fn ($item) => $item['a'],
+                [['a' => 1, 'b' => 2], ['a' => 2]],
+            ],
+            [
+                $gen([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn ($item) => $item,
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+            [
+                $gen([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn ($item) => $item['id'],
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+            [
+                $gen([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn ($item) => $item['name'],
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * @dataProvider dataProviderForIterators
+     * @param        \Iterator $data
+     * @param        callable $compareBy
+     * @param        array $expected
+     */
+    public function testIterators(\Iterator $data, callable $compareBy, array $expected): void
+    {
+        // Given
+        $result = [];
+
+        // When
+        foreach (Set::distinctBy($data, $compareBy) as $datum) {
+            $result[] = $datum;
+        }
+
+        // Then
+        $this->assertEquals($expected, $result);
+    }
+
+    public function dataProviderForIterators(): array
+    {
+        $iter = fn ($data) => new ArrayIteratorFixture($data);
+
+        return [
+            [
+                $iter([]),
+                fn ($item) => $item,
+                [],
+            ],
+            [
+                $iter([]),
+                fn ($item) => $item['name'],
+                [],
+            ],
+            [
+                $iter([1]),
+                fn ($item) => $item,
+                [1],
+            ],
+            [
+                $iter([1, 1]),
+                fn ($item) => $item,
+                [1],
+            ],
+            [
+                $iter([1, '1']),
+                fn ($item) => $item,
+                [1, '1'],
+            ],
+            [
+                $iter(['1', 1]),
+                fn ($item) => $item,
+                ['1', 1],
+            ],
+            [
+                $iter(['aa', 'bb', 'aa']),
+                fn ($item) => $item,
+                ['aa', 'bb'],
+            ],
+            [
+                $iter([1, 2, 1, 2, 3]),
+                fn ($item) => $item,
+                [1, 2, 3],
+            ],
+            [
+                $iter(['1', 2, '1', '2', 3]),
+                fn ($item) => $item,
+                ['1', 2, '2', 3],
+            ],
+            [
+                $iter(['1', 2, '1', '2', 3]),
+                fn ($item) => (int)$item,
+                ['1', 2, '3'],
+            ],
+            [
+                $iter([[1], [1], [1, 2]]),
+                fn ($item) => $item,
+                [[1], [1, 2]],
+            ],
+            [
+                $iter([[1], [1], [1, 2]]),
+                fn ($item) => $item[0],
+                [[1]],
+            ],
+            [
+                $iter([[1], 'a' => [1]]),
+                fn ($item) => $item,
+                [[1]],
+            ],
+            [
+                $iter([false, null, 0, 0.0, '']),
+                fn ($item) => $item,
+                [false, null, 0, 0.0, ''],
+            ],
+            [
+                $iter([true, 1, '1', 1.0, '1.0']),
+                fn ($item) => $item,
+                [true, 1, '1', 1.0, '1.0'],
+            ],
+            [
+                $iter([['a' => 1, 'b' => 2], ['a' => 1], ['a' => 1], 2, 2]),
+                fn ($item) => $item,
+                [['a' => 1, 'b' => 2], ['a' => 1], 2],
+            ],
+            [
+                $iter([['a' => 1, 'b' => 2], ['a' => 1], ['a' => 1], ['a' => 2]]),
+                fn ($item) => $item['a'],
+                [['a' => 1, 'b' => 2], ['a' => 2]],
+            ],
+            [
+                $iter([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn ($item) => $item,
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+            [
+                $iter([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn ($item) => $item['id'],
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+            [
+                $iter([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn ($item) => $item['name'],
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+        ];
+    }
+
+    /**
+     * @dataProvider dataProviderForTraversables
+     * @param        \Traversable $data
+     * @param        callable $compareBy
+     * @param        array $expected
+     */
+    public function testTraversables(\Traversable $data, callable $compareBy, array $expected): void
+    {
+        // Given
+        $result = [];
+
+        // When
+        foreach (Set::distinctBy($data, $compareBy) as $datum) {
+            $result[] = $datum;
+        }
+
+        // Then
+        $this->assertEquals($expected, $result);
+    }
+
+    public function dataProviderForTraversables(): array
+    {
+        $iter = fn ($data) => new IteratorAggregateFixture($data);
+
+        return [
+            [
+                $iter([]),
+                fn ($item) => $item,
+                [],
+            ],
+            [
+                $iter([]),
+                fn ($item) => $item['name'],
+                [],
+            ],
+            [
+                $iter([1]),
+                fn ($item) => $item,
+                [1],
+            ],
+            [
+                $iter([1, 1]),
+                fn ($item) => $item,
+                [1],
+            ],
+            [
+                $iter([1, '1']),
+                fn ($item) => $item,
+                [1, '1'],
+            ],
+            [
+                $iter(['1', 1]),
+                fn ($item) => $item,
+                ['1', 1],
+            ],
+            [
+                $iter(['aa', 'bb', 'aa']),
+                fn ($item) => $item,
+                ['aa', 'bb'],
+            ],
+            [
+                $iter([1, 2, 1, 2, 3]),
+                fn ($item) => $item,
+                [1, 2, 3],
+            ],
+            [
+                $iter(['1', 2, '1', '2', 3]),
+                fn ($item) => $item,
+                ['1', 2, '2', 3],
+            ],
+            [
+                $iter(['1', 2, '1', '2', 3]),
+                fn ($item) => (int)$item,
+                ['1', 2, '3'],
+            ],
+            [
+                $iter([[1], [1], [1, 2]]),
+                fn ($item) => $item,
+                [[1], [1, 2]],
+            ],
+            [
+                $iter([[1], [1], [1, 2]]),
+                fn ($item) => $item[0],
+                [[1]],
+            ],
+            [
+                $iter([[1], 'a' => [1]]),
+                fn ($item) => $item,
+                [[1]],
+            ],
+            [
+                $iter([false, null, 0, 0.0, '']),
+                fn ($item) => $item,
+                [false, null, 0, 0.0, ''],
+            ],
+            [
+                $iter([true, 1, '1', 1.0, '1.0']),
+                fn ($item) => $item,
+                [true, 1, '1', 1.0, '1.0'],
+            ],
+            [
+                $iter([['a' => 1, 'b' => 2], ['a' => 1], ['a' => 1], 2, 2]),
+                fn ($item) => $item,
+                [['a' => 1, 'b' => 2], ['a' => 1], 2],
+            ],
+            [
+                $iter([['a' => 1, 'b' => 2], ['a' => 1], ['a' => 1], ['a' => 2]]),
+                fn ($item) => $item['a'],
+                [['a' => 1, 'b' => 2], ['a' => 2]],
+            ],
+            [
+                $iter([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn ($item) => $item,
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+            [
+                $iter([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn ($item) => $item['id'],
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+            [
+                $iter([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn ($item) => $item['name'],
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
+        ];
+    }
+}
diff --git a/tests/Stream/SetTest.php b/tests/Stream/SetTest.php
index b0c7942..f97c332 100644
--- a/tests/Stream/SetTest.php
+++ b/tests/Stream/SetTest.php
@@ -51,6 +51,23 @@ public function dataProviderForArray(): array
                     ->toArray(),
                 [1, 2, 3, '1', '2', '3'],
             ],
+            [
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+                fn (iterable $iterable) => Stream::of($iterable)
+                    ->distinctBy(fn ($item) => $item['name'])
+                    ->toArray(),
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
             [
                 [
                     [1, 2, 3, 4, 5],
@@ -482,6 +499,23 @@ public function dataProviderForGenerators(): array
                     ->toArray(),
                 [1, 2, 3, '1', '2', '3'],
             ],
+            [
+                $gen([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn (iterable $iterable) => Stream::of($iterable)
+                    ->distinctBy(fn ($item) => $item['name'])
+                    ->toArray(),
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
             [
                 [
                     $gen([1, 2, 3, 4, 5]),
@@ -915,6 +949,23 @@ public function dataProviderForIterators(): array
                     ->toArray(),
                 [1, 2, 3, '1', '2', '3'],
             ],
+            [
+                $iter([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn (iterable $iterable) => Stream::of($iterable)
+                    ->distinctBy(fn ($item) => $item['name'])
+                    ->toArray(),
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
             [
                 [
                     $iter([1, 2, 3, 4, 5]),
@@ -1348,6 +1399,23 @@ public function dataProviderForTraversables(): array
                     ->toArray(),
                 [1, 2, 3, '1', '2', '3'],
             ],
+            [
+                $trav([
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Mary', 'id' => 3],
+                    ['name' => 'John', 'id' => 4],
+                    ['name' => 'Jane', 'id' => 5],
+                ]),
+                fn (iterable $iterable) => Stream::of($iterable)
+                    ->distinctBy(fn ($item) => $item['name'])
+                    ->toArray(),
+                [
+                    ['name' => 'John', 'id' => 1],
+                    ['name' => 'Mary', 'id' => 2],
+                    ['name' => 'Jane', 'id' => 5],
+                ],
+            ],
             [
                 [
                     $trav([1, 2, 3, 4, 5]),