From Jason Turner

[alg.random.shuffle]

C++17 → C++20 2.0 KB 28 lines
Current Draft | LaTeX Source
Archived: C++17 | C++20
Markdown: C++17 | C++20
Explore in Adventure Game
C++ Weekly: Ep 483

Diff to HTML by rtfpessoa

Files changed (1) hide show
  1. tmp/tmpo1d9qxbf/{from.md → to.md} +18 -7
tmp/tmpo1d9qxbf/{from.md → to.md} RENAMED
@@ -3,24 +3,35 @@
3
  ``` cpp
4
  template<class RandomAccessIterator, class UniformRandomBitGenerator>
5
  void shuffle(RandomAccessIterator first,
6
  RandomAccessIterator last,
7
  UniformRandomBitGenerator&& g);
 
 
 
 
 
 
 
 
 
8
  ```
9
 
10
- *Requires:* `RandomAccessIterator` shall satisfy the requirements of
11
- `ValueSwappable` ([[swappable.requirements]]). The type
12
- `remove_reference_t<UniformRandomBitGenerator>` shall meet the
13
- requirements of a uniform random bit generator ([[rand.req.urng]]) type
14
- whose return type is convertible to
15
- `iterator_traits<RandomAccessIterator>::difference_type`.
16
 
17
  *Effects:* Permutes the elements in the range \[`first`, `last`) such
18
  that each possible permutation of those elements has equal probability
19
  of appearance.
20
 
 
 
21
  *Complexity:* Exactly `(last - first) - 1` swaps.
22
 
23
  *Remarks:* To the extent that the implementation of this function makes
24
- use of random numbers, the object `g` shall serve as the
25
  implementation’s source of randomness.
26
 
 
3
  ``` cpp
4
  template<class RandomAccessIterator, class UniformRandomBitGenerator>
5
  void shuffle(RandomAccessIterator first,
6
  RandomAccessIterator last,
7
  UniformRandomBitGenerator&& g);
8
+
9
+ template<random_access_iterator I, sentinel_for<I> S, class Gen>
10
+ requires permutable<I> &&
11
+ uniform_random_bit_generator<remove_reference_t<Gen>>
12
+ I ranges::shuffle(I first, S last, Gen&& g);
13
+ template<random_access_range R, class Gen>
14
+ requires permutable<iterator_t<R>> &&
15
+ uniform_random_bit_generator<remove_reference_t<Gen>>
16
+ borrowed_iterator_t<R> ranges::shuffle(R&& r, Gen&& g);
17
  ```
18
 
19
+ *Preconditions:* For the overload in namespace `std`:
20
+
21
+ - `RandomAccessIterator` meets the *Cpp17ValueSwappable*
22
+ requirements [[swappable.requirements]].
23
+ - The type `remove_reference_t<UniformRandomBitGenerator>` meets the
24
+ uniform random bit generator [[rand.req.urng]] requirements.
25
 
26
  *Effects:* Permutes the elements in the range \[`first`, `last`) such
27
  that each possible permutation of those elements has equal probability
28
  of appearance.
29
 
30
+ *Returns:* `last` for the overloads in namespace `ranges`.
31
+
32
  *Complexity:* Exactly `(last - first) - 1` swaps.
33
 
34
  *Remarks:* To the extent that the implementation of this function makes
35
+ use of random numbers, the object referenced by `g` shall serve as the
36
  implementation’s source of randomness.
37