SGIextensions

Functions
namespace __gnu_cxx	_GLIBCXX_VISIBILITY (default)

Detailed Description

The identity_element functions are not part of the C++ standard; SGI provided them as an extension. Its argument is an operation, and its return value is the identity element for that operation. It is overloaded for addition and multiplication, and you can overload it for your own nefarious operations.

As an extension to the binders, SGI provided composition functors and wrapper functions to aid in their creation. The unary_compose functor is constructed from two functions/functors, f and g. Calling operator() with a single argument x returns f(g(x)). The function compose1 takes the two functions and constructs a unary_compose variable for you.

binary_compose is constructed from three functors, f, g1, and g2. Its operator() returns f(g1(x),g2(x)). The function compose2 takes f, g1, and g2, and constructs the binary_compose instance for you. For example, if f returns an int, then

int answer = (compose2(f,g1,g2))(x);

is equivalent to

int temp1 = g1(x);
int temp2 = g2(x);
int answer = f(temp1,temp2);

But the first form is more compact, and can be passed around as a functor to other algorithms.

As an extension, SGI provided a functor called identity. When a functor is required but no operations are desired, this can be used as a pass-through. Its operator() returns its argument unchanged.

select1st and select2nd are extensions provided by SGI. Their operator()s take a std::pair as an argument, and return either the first member or the second member, respectively. They can be used (especially with the composition functors) to strip data from a sequence before performing the remainder of an algorithm.

The operator() of the project1st functor takes two arbitrary arguments and returns the first one, while project2nd returns the second one. They are extensions provided by SGI.

These three functors are each constructed from a single arbitrary variable/value. Later, their operator()s completely ignore any arguments passed, and return the stored value.

• constant_void_fun's operator() takes no arguments
• constant_unary_fun's operator() takes one argument (ignored)
• constant_binary_fun's operator() takes two arguments (ignored)

The helper creator functions constant0, constant1, and constant2 each take a result argument and construct variables of the appropriate functor type.

Function Documentation

namespace __gnu_cxx _GLIBCXX_VISIBILITY

(

default

)

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

Copies the range [first,first+count) into [result,result+count).

Parameters

__first	An input iterator.
__count	The number of elements to copy.
__result	An output iterator.

Returns

A std::pair composed of first+count and result+count.

This is an SGI extension. This inline function will boil down to a call to memmove whenever possible. Failing that, if random access iterators are passed, then the loop count will be known (and therefore a candidate for compiler optimizations such as unrolling).

memcmp on steroids.

Parameters

__first1	An input iterator.
__last1	An input iterator.
__first2	An input iterator.
__last2	An input iterator.

Returns

An int, as with memcmp.

The return value will be less than zero if the first range is lexigraphically less than the second, greater than zero if the second range is lexigraphically less than the first, and zero otherwise. This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

Find the median of three values.

Parameters

__a	A value.
__b	A value.
__c	A value.

Returns

One of a, b or c.

If {l,m,n} is some convolution of {a,b,c} such that l<=m<=n then the value returned will be m. This is an SGI extension.

Find the median of three values using a predicate for comparison.

Parameters

__a	A value.
__b	A value.
__c	A value.
__comp	A binary predicate.

Returns

One of a, b or c.

If {l,m,n} is some convolution of {a,b,c} such that comp(l,m) and comp(m,n) are both true then the value returned will be m. This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

Copies the range [first,last) into result.

Parameters

__first	An input iterator.
__count	Length
__result	An output iterator.

Returns

__result + (__first + __count)

Like copy(), but does not require an initialized output range.

This class provides similar behavior and semantics of the standard functions get_temporary_buffer() and return_temporary_buffer(), but encapsulated in a type vaguely resembling a standard container.

By default, a temporary_buffer<Iter> stores space for objects of whatever type the Iter iterator points to. It is constructed from a typical [first,last) range, and provides the begin(), end(), size() functions, as well as requested_size(). For non-trivial types, copies of *first will be used to initialize the storage.

malloc is used to obtain underlying storage.

Like get_temporary_buffer(), not all the requested memory may be available. Ideally, the created buffer will be large enough to hold a copy of [first,last), but if size() is less than requested_size(), then this didn't happen.

Requests storage large enough to hold a copy of [first,last).

Destroys objects and frees storage.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

This is an SGI extension.

{
_GLIBCXX_BEGIN_NAMESPACE_VERSION

  using std::equal_to;
  using std::allocator;
  using std::pair;
  using std::_Select1st;

  template<class _Key, class _Tp, class _HashFn = hash<_Key>,
       class _EqualKey = equal_to<_Key>, class _Alloc = allocator<_Tp> >
    class hash_map
    {
    private:
      typedef hashtable<pair<const _Key, _Tp>,_Key, _HashFn,
            _Select1st<pair<const _Key, _Tp> >,
            _EqualKey, _Alloc> _Ht;

      _Ht _M_ht;

    public:
      typedef typename _Ht::key_type key_type;
      typedef _Tp data_type;
      typedef _Tp mapped_type;
      typedef typename _Ht::value_type value_type;
      typedef typename _Ht::hasher hasher;
      typedef typename _Ht::key_equal key_equal;
      
      typedef typename _Ht::size_type size_type;
      typedef typename _Ht::difference_type difference_type;
      typedef typename _Ht::pointer pointer;
      typedef typename _Ht::const_pointer const_pointer;
      typedef typename _Ht::reference reference;
      typedef typename _Ht::const_reference const_reference;
      
      typedef typename _Ht::iterator iterator;
      typedef typename _Ht::const_iterator const_iterator;
      
      typedef typename _Ht::allocator_type allocator_type;
      
      hasher
      hash_funct() const
      { return _M_ht.hash_funct(); }

      key_equal
      key_eq() const
      { return _M_ht.key_eq(); }

      allocator_type
      get_allocator() const
      { return _M_ht.get_allocator(); }

      hash_map()
      : _M_ht(100, hasher(), key_equal(), allocator_type()) {}
  
      explicit
      hash_map(size_type __n)
      : _M_ht(__n, hasher(), key_equal(), allocator_type()) {}

      hash_map(size_type __n, const hasher& __hf)
      : _M_ht(__n, __hf, key_equal(), allocator_type()) {}

      hash_map(size_type __n, const hasher& __hf, const key_equal& __eql,
           const allocator_type& __a = allocator_type())
      : _M_ht(__n, __hf, __eql, __a) {}

      template<class _InputIterator>
        hash_map(_InputIterator __f, _InputIterator __l)
    : _M_ht(100, hasher(), key_equal(), allocator_type())
        { _M_ht.insert_unique(__f, __l); }

      template<class _InputIterator>
        hash_map(_InputIterator __f, _InputIterator __l, size_type __n)
    : _M_ht(__n, hasher(), key_equal(), allocator_type())
        { _M_ht.insert_unique(__f, __l); }

      template<class _InputIterator>
        hash_map(_InputIterator __f, _InputIterator __l, size_type __n,
         const hasher& __hf)
    : _M_ht(__n, __hf, key_equal(), allocator_type())
        { _M_ht.insert_unique(__f, __l); }

      template<class _InputIterator>
        hash_map(_InputIterator __f, _InputIterator __l, size_type __n,
         const hasher& __hf, const key_equal& __eql,
         const allocator_type& __a = allocator_type())
    : _M_ht(__n, __hf, __eql, __a)
        { _M_ht.insert_unique(__f, __l); }

      size_type
      size() const
      { return _M_ht.size(); }
      
      size_type
      max_size() const
      { return _M_ht.max_size(); }
      
      bool
      empty() const
      { return _M_ht.empty(); }
  
      void
      swap(hash_map& __hs)
      { _M_ht.swap(__hs._M_ht); }

      template<class _K1, class _T1, class _HF, class _EqK, class _Al>
        friend bool
        operator== (const hash_map<_K1, _T1, _HF, _EqK, _Al>&,
            const hash_map<_K1, _T1, _HF, _EqK, _Al>&);

      iterator
      begin()
      { return _M_ht.begin(); }

      iterator
      end()
      { return _M_ht.end(); }

      const_iterator
      begin() const
      { return _M_ht.begin(); }

      const_iterator
      end() const
      { return _M_ht.end(); }

      pair<iterator, bool>
      insert(const value_type& __obj)
      { return _M_ht.insert_unique(__obj); }

      template<class _InputIterator>
        void
        insert(_InputIterator __f, _InputIterator __l)
        { _M_ht.insert_unique(__f, __l); }

      pair<iterator, bool>
      insert_noresize(const value_type& __obj)
      { return _M_ht.insert_unique_noresize(__obj); }

      iterator
      find(const key_type& __key)
      { return _M_ht.find(__key); }

      const_iterator
      find(const key_type& __key) const
      { return _M_ht.find(__key); }

      _Tp&
      operator[](const key_type& __key)
      { return _M_ht.find_or_insert(value_type(__key, _Tp())).second; }

      size_type
      count(const key_type& __key) const
      { return _M_ht.count(__key); }

      pair<iterator, iterator>
      equal_range(const key_type& __key)
      { return _M_ht.equal_range(__key); }

      pair<const_iterator, const_iterator>
      equal_range(const key_type& __key) const
      { return _M_ht.equal_range(__key); }

      size_type
      erase(const key_type& __key)
      {return _M_ht.erase(__key); }

      void
      erase(iterator __it)
      { _M_ht.erase(__it); }

      void
      erase(iterator __f, iterator __l)
      { _M_ht.erase(__f, __l); }

      void
      clear()
      { _M_ht.clear(); }

      void
      resize(size_type __hint)
      { _M_ht.resize(__hint); }

      size_type
      bucket_count() const
      { return _M_ht.bucket_count(); }

      size_type
      max_bucket_count() const
      { return _M_ht.max_bucket_count(); }

      size_type
      elems_in_bucket(size_type __n) const
      { return _M_ht.elems_in_bucket(__n); }
    };

  template<class _Key, class _Tp, class _HashFn, class _EqlKey, class _Alloc>
    inline bool
    operator==(const hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm1,
           const hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm2)
    { return __hm1._M_ht == __hm2._M_ht; }

  template<class _Key, class _Tp, class _HashFn, class _EqlKey, class _Alloc>
    inline bool
    operator!=(const hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm1,
           const hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm2)
    { return !(__hm1 == __hm2); }

  template<class _Key, class _Tp, class _HashFn, class _EqlKey, class _Alloc>
    inline void
    swap(hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm1,
     hash_map<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm2)
    { __hm1.swap(__hm2); }


  template<class _Key, class _Tp,
       class _HashFn = hash<_Key>,
       class _EqualKey = equal_to<_Key>,
       class _Alloc = allocator<_Tp> >
    class hash_multimap
    {
      // concept requirements
      __glibcxx_class_requires(_Key, _SGIAssignableConcept)
      __glibcxx_class_requires(_Tp, _SGIAssignableConcept)
      __glibcxx_class_requires3(_HashFn, size_t, _Key, _UnaryFunctionConcept)
      __glibcxx_class_requires3(_EqualKey, _Key, _Key, _BinaryPredicateConcept)
    
    private:
      typedef hashtable<pair<const _Key, _Tp>, _Key, _HashFn,
            _Select1st<pair<const _Key, _Tp> >, _EqualKey, _Alloc>
          _Ht;

      _Ht _M_ht;

    public:
      typedef typename _Ht::key_type key_type;
      typedef _Tp data_type;
      typedef _Tp mapped_type;
      typedef typename _Ht::value_type value_type;
      typedef typename _Ht::hasher hasher;
      typedef typename _Ht::key_equal key_equal;
      
      typedef typename _Ht::size_type size_type;
      typedef typename _Ht::difference_type difference_type;
      typedef typename _Ht::pointer pointer;
      typedef typename _Ht::const_pointer const_pointer;
      typedef typename _Ht::reference reference;
      typedef typename _Ht::const_reference const_reference;
      
      typedef typename _Ht::iterator iterator;
      typedef typename _Ht::const_iterator const_iterator;
      
      typedef typename _Ht::allocator_type allocator_type;
      
      hasher
      hash_funct() const
      { return _M_ht.hash_funct(); }

      key_equal
      key_eq() const
      { return _M_ht.key_eq(); }

      allocator_type
      get_allocator() const
      { return _M_ht.get_allocator(); }

      hash_multimap()
      : _M_ht(100, hasher(), key_equal(), allocator_type()) {}

      explicit
      hash_multimap(size_type __n)
      : _M_ht(__n, hasher(), key_equal(), allocator_type()) {}

      hash_multimap(size_type __n, const hasher& __hf)
      : _M_ht(__n, __hf, key_equal(), allocator_type()) {}

      hash_multimap(size_type __n, const hasher& __hf, const key_equal& __eql,
            const allocator_type& __a = allocator_type())
      : _M_ht(__n, __hf, __eql, __a) {}

      template<class _InputIterator>
        hash_multimap(_InputIterator __f, _InputIterator __l)
    : _M_ht(100, hasher(), key_equal(), allocator_type())
        { _M_ht.insert_equal(__f, __l); }

      template<class _InputIterator>
        hash_multimap(_InputIterator __f, _InputIterator __l, size_type __n)
    : _M_ht(__n, hasher(), key_equal(), allocator_type())
        { _M_ht.insert_equal(__f, __l); }

      template<class _InputIterator>
        hash_multimap(_InputIterator __f, _InputIterator __l, size_type __n,
              const hasher& __hf)
    : _M_ht(__n, __hf, key_equal(), allocator_type())
        { _M_ht.insert_equal(__f, __l); }

      template<class _InputIterator>
        hash_multimap(_InputIterator __f, _InputIterator __l, size_type __n,
              const hasher& __hf, const key_equal& __eql,
              const allocator_type& __a = allocator_type())
    : _M_ht(__n, __hf, __eql, __a)
        { _M_ht.insert_equal(__f, __l); }

      size_type
      size() const
      { return _M_ht.size(); }

      size_type
      max_size() const
      { return _M_ht.max_size(); }

      bool
      empty() const
      { return _M_ht.empty(); }

      void
      swap(hash_multimap& __hs)
      { _M_ht.swap(__hs._M_ht); }

      template<class _K1, class _T1, class _HF, class _EqK, class _Al>
        friend bool
        operator==(const hash_multimap<_K1, _T1, _HF, _EqK, _Al>&,
           const hash_multimap<_K1, _T1, _HF, _EqK, _Al>&);

      iterator
      begin()
      { return _M_ht.begin(); }

      iterator
      end()
      { return _M_ht.end(); }

      const_iterator
      begin() const
      { return _M_ht.begin(); }

      const_iterator
      end() const
      { return _M_ht.end(); }

      iterator
      insert(const value_type& __obj)
      { return _M_ht.insert_equal(__obj); }

      template<class _InputIterator>
        void
        insert(_InputIterator __f, _InputIterator __l)
        { _M_ht.insert_equal(__f,__l); }

      iterator
      insert_noresize(const value_type& __obj)
      { return _M_ht.insert_equal_noresize(__obj); }

      iterator
      find(const key_type& __key)
      { return _M_ht.find(__key); }

      const_iterator
      find(const key_type& __key) const
      { return _M_ht.find(__key); }

      size_type
      count(const key_type& __key) const
      { return _M_ht.count(__key); }

      pair<iterator, iterator>
      equal_range(const key_type& __key)
      { return _M_ht.equal_range(__key); }

      pair<const_iterator, const_iterator>
      equal_range(const key_type& __key) const
      { return _M_ht.equal_range(__key); }

      size_type
      erase(const key_type& __key)
      { return _M_ht.erase(__key); }

      void
      erase(iterator __it)
      { _M_ht.erase(__it); }

      void
      erase(iterator __f, iterator __l)
      { _M_ht.erase(__f, __l); }

      void
      clear()
      { _M_ht.clear(); }

      void
      resize(size_type __hint)
      { _M_ht.resize(__hint); }

      size_type
      bucket_count() const
      { return _M_ht.bucket_count(); }

      size_type
      max_bucket_count() const
      { return _M_ht.max_bucket_count(); }
      
      size_type
      elems_in_bucket(size_type __n) const
      { return _M_ht.elems_in_bucket(__n); }
    };

  template<class _Key, class _Tp, class _HF, class _EqKey, class _Alloc>
    inline bool
    operator==(const hash_multimap<_Key, _Tp, _HF, _EqKey, _Alloc>& __hm1,
           const hash_multimap<_Key, _Tp, _HF, _EqKey, _Alloc>& __hm2)
    { return __hm1._M_ht == __hm2._M_ht; }

  template<class _Key, class _Tp, class _HF, class _EqKey, class _Alloc>
    inline bool
    operator!=(const hash_multimap<_Key, _Tp, _HF, _EqKey, _Alloc>& __hm1,
           const hash_multimap<_Key, _Tp, _HF, _EqKey, _Alloc>& __hm2)
    { return !(__hm1 == __hm2); }

  template<class _Key, class _Tp, class _HashFn, class _EqlKey, class _Alloc>
    inline void
    swap(hash_multimap<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm1,
     hash_multimap<_Key, _Tp, _HashFn, _EqlKey, _Alloc>& __hm2)
    { __hm1.swap(__hm2); }

_GLIBCXX_END_NAMESPACE_VERSION
} // namespace