Template Class primes_iterator

Defined in File primes.hpp

Class Documentation

template<class PRIMES_IMPLEMENTATION = euler_sieve_sqrt> class primes_iterator

Iterator for primes.

Conforms to the std::random_access_iterator concept, so primes can be accessed safely in a random order. Scanning from low to high values is still suggested, as well as using primes’s .calculate_primes_through(n) function to calculate only the primes needed rather than the automatic expansion logic which will be costly.

Public Types

using value_type = typename madlib::prime_type : Iterator’s data type for primes, defined as madlib::prime_type .

using difference_type = ssize_t: Type for distance between iterators, required by std::random_access_iterator .

Public Functions

inline primes_iterator()

inline explicit primes_iterator(primes<PRIMES_IMPLEMENTATION> *from): Actual default constructor, taking the primes object to reference and defaulting to the first prime.

inline explicit primes_iterator(primes<PRIMES_IMPLEMENTATION> *from, const unsigned_integral auto &initial_idx): Constructor specifying the primes object to take from and which prime to start on.

inline primes_iterator<PRIMES_IMPLEMENTATION> &operator++(): Cause the iterator to point to the next prime in place.

inline primes_iterator<PRIMES_IMPLEMENTATION> operator++(int): Return an iterator pointing to the next prime number.

inline primes_iterator<PRIMES_IMPLEMENTATION> &operator--(): Cause the iterator to point to the previous prime in place.

inline primes_iterator<PRIMES_IMPLEMENTATION> operator--(int): Return an iterator pointing to the previous prime number.

inline value_type operator*() const: Return the prime number pointed to by this instance of the iterator. Will dynamically expand the number of primes mapped by the owning primes class as needed.

inline bool operator==(primes_iterator_sentinel_t): There are infinite primes, so use a Sentinel Iterator to represent this.

template<class PRIMES_IMPLEMENTATION_OTHER> inline auto operator<=>(const primes_iterator<PRIMES_IMPLEMENTATION_OTHER> &rhs) const: Generate all comparison operators. Does not compare if the owning primes object is the same.

inline value_type operator[](const integral auto &index_from) const: Access a prime whose index is the sum of this instance’s index and the index passed.

Friends

friend primes_iterator<PRIMES_IMPLEMENTATION> operator+(const integral auto &lhs, const primes_iterator<PRIMES_IMPLEMENTATION> &rhs): Increment the prime rhs pointed by lhs times.

friend primes_iterator<PRIMES_IMPLEMENTATION> operator+(const primes_iterator<PRIMES_IMPLEMENTATION> &lhs, const integral auto &rhs): Increment the prime lhs pointed by rhs times.

friend primes_iterator<PRIMES_IMPLEMENTATION> &operator+=(primes_iterator<PRIMES_IMPLEMENTATION> &lhs, const integral auto &rhs): Increment the prime lhs pointed in place by rhs times.

friend primes_iterator<PRIMES_IMPLEMENTATION> operator-(const integral auto &lhs, const primes_iterator<PRIMES_IMPLEMENTATION> &rhs): Decrement the prime rhs pointed by lhs times.

friend primes_iterator<PRIMES_IMPLEMENTATION> operator-(const primes_iterator<PRIMES_IMPLEMENTATION> &lhs, const integral auto &rhs): Decrement the prime lhs pointed by rhs times.

template<class PRIMES_IMPLEMENTATION_OTHER> friend difference_type operator-(const primes_iterator<PRIMES_IMPLEMENTATION> &lhs, const primes_iterator<PRIMES_IMPLEMENTATION_OTHER> &rhs): Returns the distance in number of primes between one lhs and rhs.

friend primes_iterator<PRIMES_IMPLEMENTATION> &operator-=(primes_iterator<PRIMES_IMPLEMENTATION> &lhs, const integral auto &rhs): Increment the prime lhs pointed in place by rhs times.

template<class PRIMES_IMPLEMENTATION_OTHER> inline friend bool operator==(const primes_iterator<PRIMES_IMPLEMENTATION> &lhs, const primes_iterator<PRIMES_IMPLEMENTATION_OTHER> &rhs): Equality operator required by std::random_access_iterator, ignores owning primes object for comparisons.