Remove transform_iterator and related, no clear need for it yet

src/MemoryX.h

@@ -611,96 +611,6 @@ make_iterator_range( const Container &container )
    return { container.begin(), container.end() };
 }
 
-/*
- * Transform an iterator sequence, as another iterator sequence
- */
-template <
-   typename Result,
-   typename Iterator
->
-class transform_iterator
-   : public std::iterator<
-      typename std::iterator_traits<Iterator>::iterator_category,
-      const Result
-   >
-{
-   // This takes a function on iterators themselves, not on the
-   // dereference of those iterators, in case you ever need the generality.
-   using Function = std::function< Result( const Iterator& ) >;
-
-private:
-   Iterator mIterator;
-   Function mFunction;
-
-public:
-   transform_iterator(const Iterator &iterator, const Function &function)
-      : mIterator( iterator )
-      , mFunction( function )
-   {}
-
-   transform_iterator &operator ++ ()
-      { ++this->mIterator; return *this; }
-   transform_iterator operator ++ (int)
-      { auto copy{*this}; ++this->mIterator; return copy; }
-   transform_iterator &operator -- ()
-      { --this->mIterator; return *this; }
-   transform_iterator operator -- (int)
-      { auto copy{*this}; --this->mIterator; return copy; }
-
-   Result operator * ()
-      { return this->mFunction(this->mIterator); }
-
-   friend inline bool operator == (
-      const transform_iterator &a, const transform_iterator &b)
-      { return a.mIterator == b.mIterator; }
-   friend inline bool operator != (
-      const transform_iterator &a, const transform_iterator &b)
-      { return !(a == b); }
-};
-
-template <
-   typename Iterator,
-   typename Function
->
-transform_iterator<
-   decltype( std::declval<Function>() ( std::declval<Iterator>() ) ),
-   Iterator
->
-make_transform_iterator(const Iterator &iterator, Function function)
-{
-   return { iterator, function };
-}
-
-template < typename Function, typename Iterator > struct value_transformer
-{
-   // Adapts a function on values to a function on iterators.
-   Function function;
-
-   auto operator () (const Iterator &iterator) const
-      -> decltype( function( *iterator ) )
-   { return this->function( *iterator ); }
-};
-
-template <
-   typename Function,
-   typename Iterator
->
-using value_transform_iterator = transform_iterator<
-   decltype( std::declval<Function>()( *std::declval<Iterator>() ) ),
-   Iterator
->;
-
-template <
-   typename Function,
-   typename Iterator
->
-value_transform_iterator< Function, Iterator >
-make_value_transform_iterator(const Iterator &iterator, Function function)
-{
-   using NewFunction = value_transformer<Function, Iterator>;
-   return { iterator, NewFunction{ function } };
-}
-
 #if !wxCHECK_VERSION(3, 1, 0)
 // For using std::unordered_map on wxString
 namespace std