Pill.hpp

   1 #ifndef PILL_DOT_HPP
   2 #define PILL_DOT_HPP
   3
   4 #include <climits>
   5 #include <cstddef>
   6 #include <cstring>
   7 #include <ostream>
   8 #include <string_view>
   9
  10 #include "pcg.hpp"
  11
  12 // A pill is a unit of entropy.
  13
  14 class Pill {
  15 public:
  16   Pill();
  17
  18   bool operator==(Pill const& that) const { return this->s_ == that.s_; }
  19   bool operator!=(Pill const& that) const { return !(*this == that); }
  20
  21   std::string_view as_string_view() const
  22   {
  23     return std::string_view{b32_str_, b32_ndigits_};
  24   }
  25
  26 private:
  27   unsigned long long s_;
  28
  29   auto static constexpr b32_ndigits_ = ((sizeof(s_) * CHAR_BIT) + 4) / 5;
  30   char b32_str_[b32_ndigits_ + 1];
  31
  32   friend std::ostream& operator<<(std::ostream& s, Pill const& p)
  33   {
  34     return s << p.as_string_view();
  35   }
  36
  37   inline static pcg_extras::seed_seq_from<std::random_device> seed_source_;
  38   inline static pcg64 rng_{seed_source_};
  39 };
  40
  41 #endif // PILL_DOT_HPP