From Jason Turner

[rand.eng.sub]

C++23 → Trunk 2.7 KB 21 lines
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Archived: C++23
Markdown: C++23 | Trunk
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  1. tmp/tmph6rlvzdm/{from.md → to.md} +9 -7
tmp/tmph6rlvzdm/{from.md → to.md} RENAMED
@@ -33,17 +33,17 @@ namespace std {
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  static constexpr size_t word_size = w;
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  static constexpr size_t short_lag = s;
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  static constexpr size_t long_lag = r;
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  static constexpr result_type min() { return 0; }
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  static constexpr result_type max() { return m - 1; }
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- static constexpr result_type default_seed = 19780503u;
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  // constructors and seeding functions
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- subtract_with_carry_engine() : subtract_with_carry_engine(default_seed) {}
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  explicit subtract_with_carry_engine(result_type value);
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  template<class Sseq> explicit subtract_with_carry_engine(Sseq& q);
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- void seed(result_type value = default_seed);
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  template<class Sseq> void seed(Sseq& q);
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  // equality operators
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  friend bool operator==(const subtract_with_carry_engine& x,
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  const subtract_with_carry_engine& y);
@@ -53,14 +53,16 @@ namespace std {
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  void discard(unsigned long long z);
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  // inserters and extractors
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  template<class charT, class traits>
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  friend basic_ostream<charT, traits>&
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- operator<<(basic_ostream<charT, traits>& os, const subtract_with_carry_engine& x);
 
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  template<class charT, class traits>
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  friend basic_istream<charT, traits>&
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- operator>>(basic_istream<charT, traits>& is, subtract_with_carry_engine& x);
 
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  };
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  }
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  ```
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  The following relations shall hold: `0u < s`, `s < r`, `0 < w`, and
@@ -78,12 +80,12 @@ below. If X₋₁ is then 0, sets c to 1; otherwise sets c to 0.
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  To set the values Xₖ, first construct `e`, a
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  `linear_congruential_engine` object, as if by the following definition:
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  ``` cpp
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- linear_congruential_engine<result_type,
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- 40014u,0u,2147483563u> e(value == 0u ? default_seed : value);
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  ```
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  Then, to set each Xₖ, obtain new values z₀, …, zₙ₋₁ from n = ⌈ w/32 ⌉
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  successive invocations of `e`. Set Xₖ to
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  $\left( \sum_{j=0}^{n-1} z_j \cdot 2^{32j}\right) \bmod m$.
 
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  static constexpr size_t word_size = w;
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  static constexpr size_t short_lag = s;
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  static constexpr size_t long_lag = r;
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  static constexpr result_type min() { return 0; }
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  static constexpr result_type max() { return m - 1; }
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+ static constexpr uint_least32_t default_seed = 19780503u;
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  // constructors and seeding functions
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+ subtract_with_carry_engine() : subtract_with_carry_engine(0u) {}
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  explicit subtract_with_carry_engine(result_type value);
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  template<class Sseq> explicit subtract_with_carry_engine(Sseq& q);
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+ void seed(result_type value = 0u);
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  template<class Sseq> void seed(Sseq& q);
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  // equality operators
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  friend bool operator==(const subtract_with_carry_engine& x,
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  const subtract_with_carry_engine& y);
 
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  void discard(unsigned long long z);
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  // inserters and extractors
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  template<class charT, class traits>
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  friend basic_ostream<charT, traits>&
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+ operator<<(basic_ostream<charT, traits>& os, // hosted
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+ const subtract_with_carry_engine& x);
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  template<class charT, class traits>
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  friend basic_istream<charT, traits>&
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+ operator>>(basic_istream<charT, traits>& is, // hosted
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+ subtract_with_carry_engine& x);
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  };
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  }
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  ```
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  The following relations shall hold: `0u < s`, `s < r`, `0 < w`, and
 
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  To set the values Xₖ, first construct `e`, a
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  `linear_congruential_engine` object, as if by the following definition:
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  ``` cpp
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+ linear_congruential_engine<uint_least32_t, 40014u, 0u, 2147483563u> e(
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+ value == 0u ? default_seed : static_cast<uint_least32_t>(value % 2147483563u));
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  ```
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  Then, to set each Xₖ, obtain new values z₀, …, zₙ₋₁ from n = ⌈ w/32 ⌉
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  successive invocations of `e`. Set Xₖ to
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  $\left( \sum_{j=0}^{n-1} z_j \cdot 2^{32j}\right) \bmod m$.