string.hpp

来自「Boost provides free peer-reviewed portab」· HPP 代码 · 共 1,794 行 · 第 1/5 页

   void priv_addr(pointer addr)
   {  this->members_.m_repr.long_repr().start = addr;  }

   size_type priv_storage() const
   {  return this->is_short() ? InternalBufferChars : this->members_.m_repr.long_repr().storage;  }

   void priv_storage(size_type storage)
   {  
      if(!this->is_short())
         this->members_.m_repr.long_repr().storage = storage;
   }

   size_type priv_size() const
   {  return this->is_short() ? this->members_.m_repr.short_repr().h.length : this->members_.m_repr.long_repr().length;  }

   void priv_size(size_type sz)
   {  
      if(this->is_short())
         this->members_.m_repr.s.h.length = (unsigned char)sz;
      else
         this->members_.m_repr.long_repr().length = static_cast<typename A::size_type>(sz);
   }

   void swap(basic_string_base& other) 
   {
      if(this->is_short()){
         if(other.is_short()){
            std::swap(this->members_.m_repr, other.members_.m_repr);
         }
         else{
            repr_t copied(this->members_.m_repr);
            this->members_.m_repr.long_repr() = other.members_.m_repr.long_repr();
            other.members_.m_repr = copied;
         }
      }
      else{
         if(other.is_short()){
            repr_t copied(other.members_.m_repr);
            other.members_.m_repr.long_repr() = this->members_.m_repr.long_repr();
            this->members_.m_repr = copied;
         }
         else{
            std::swap(this->members_.m_repr.long_repr(), other.members_.m_repr.long_repr());
         }
      }

      allocator_type & this_al = this->alloc(), &other_al = other.alloc();
      if(this_al != other_al){
         detail::do_swap(this_al, other_al);
      }
   }
};
/// @endcond

}  //namespace detail {


//! The basic_string class represents a Sequence of characters. It contains all the 
//! usual operations of a Sequence, and, additionally, it contains standard string 
//! operations such as search and concatenation.
//!
//! The basic_string class is parameterized by character type, and by that type's 
//! Character Traits.
//! 
//! This class has performance characteristics very much like vector<>, meaning, 
//! for example, that it does not perform reference-count or copy-on-write, and that
//! concatenation of two strings is an O(N) operation. 
//! 
//! Some of basic_string's member functions use an unusual method of specifying positions 
//! and ranges. In addition to the conventional method using iterators, many of 
//! basic_string's member functions use a single value pos of type size_type to represent a 
//! position (in which case the position is begin() + pos, and many of basic_string's 
//! member functions use two values, pos and n, to represent a range. In that case pos is 
//! the beginning of the range and n is its size. That is, the range is 
//! [begin() + pos, begin() + pos + n). 
//! 
//! Note that the C++ standard does not specify the complexity of basic_string operations. 
//! In this implementation, basic_string has performance characteristics very similar to 
//! those of vector: access to a single character is O(1), while copy and concatenation 
//! are O(N).
//! 
//! In this implementation, begin(), 
//! end(), rbegin(), rend(), operator[], c_str(), and data() do not invalidate iterators.
//! In this implementation, iterators are only invalidated by member functions that
//! explicitly change the string's contents. 
template <class CharT, class Traits, class A> 
class basic_string
   :  private detail::basic_string_base<A> 
{
   /// @cond
   private:
   typedef detail::basic_string_base<A> base_t;
   static const typename base_t::size_type InternalBufferChars = base_t::InternalBufferChars;

   protected:
   // A helper class to use a char_traits as a function object.

   template <class Tr>
   struct Eq_traits
      : public std::binary_function<typename Tr::char_type,
                                    typename Tr::char_type,
                                    bool>
   {
      bool operator()(const typename Tr::char_type& x,
                      const typename Tr::char_type& y) const
         { return Tr::eq(x, y); }
   };

   template <class Tr>
   struct Not_within_traits
      : public std::unary_function<typename Tr::char_type, bool>
   {
      typedef const typename Tr::char_type* Pointer;
      const Pointer m_first;
      const Pointer m_last;

      Not_within_traits(Pointer f, Pointer l) 
         : m_first(f), m_last(l) {}

      bool operator()(const typename Tr::char_type& x) const 
      {
         return std::find_if(m_first, m_last, 
                        std::bind1st(Eq_traits<Tr>(), x)) == m_last;
      }
   };
   /// @endcond

   public:
   //! The allocator type
   typedef A                                       allocator_type;
   //! The stored allocator type
   typedef allocator_type                          stored_allocator_type;
   //! The type of object, CharT, stored in the string
   typedef CharT                                   value_type;
   //! The second template parameter Traits
   typedef Traits                                  traits_type;
   //! Pointer to CharT
   typedef typename A::pointer                     pointer;
   //! Const pointer to CharT 
   typedef typename A::const_pointer               const_pointer;
   //! Reference to CharT 
   typedef typename A::reference                   reference;
   //! Const reference to CharT 
   typedef typename A::const_reference             const_reference;
   //! An unsigned integral type
   typedef typename A::size_type                   size_type;
   //! A signed integral type
   typedef typename A::difference_type             difference_type;
   //! Iterator used to iterate through a string. It's a Random Access Iterator
   typedef pointer                                 iterator;
   //! Const iterator used to iterate through a string. It's a Random Access Iterator
   typedef const_pointer                           const_iterator;
   //! Iterator used to iterate backwards through a string
   typedef std::reverse_iterator<iterator>       reverse_iterator;
   //! Const iterator used to iterate backwards through a string
   typedef std::reverse_iterator<const_iterator> const_reverse_iterator;
   //! The largest possible value of type size_type. That is, size_type(-1). 
   static const size_type npos;

   /// @cond
   private:
   typedef constant_iterator<CharT, difference_type> cvalue_iterator;
   /// @endcond

   public:                         // Constructor, destructor, assignment.
   /// @cond
   struct reserve_t {};
   /// @endcond

   basic_string(reserve_t, std::size_t n,
               const allocator_type& a = allocator_type())
      : base_t(a, n + 1)
   { this->priv_terminate_string(); }

   //! <b>Effects</b>: Constructs a basic_string taking the allocator as parameter.
   //! 
   //! <b>Throws</b>: If allocator_type's copy constructor throws.
   explicit basic_string(const allocator_type& a = allocator_type())
      : base_t(a, InternalBufferChars)
   { this->priv_terminate_string(); }

   //! <b>Effects</b>: Copy constructs a basic_string.
   //!
   //! <b>Postcondition</b>: x == *this.
   //! 
   //! <b>Throws</b>: If allocator_type's default constructor or copy constructor throws.
   basic_string(const basic_string& s) 
      : base_t(s.alloc()) 
   { this->priv_range_initialize(s.begin(), s.end()); }

   //! <b>Effects</b>: Move constructor. Moves mx's resources to *this.
   //!
   //! <b>Throws</b>: If allocator_type's copy constructor throws.
   //! 
   //! <b>Complexity</b>: Constant.
   #ifndef BOOST_INTERPROCESS_RVALUE_REFERENCE
   basic_string(const detail::moved_object<basic_string>& s) 
      : base_t(detail::move_impl((base_t&)s.get()))
   {}
   #else
   basic_string(basic_string && s) 
      : base_t(detail::move_impl((base_t&)s))
   {}
   #endif

   //! <b>Effects</b>: Constructs a basic_string taking the allocator as parameter,
   //!   and is initialized by a specific number of characters of the s string. 
   basic_string(const basic_string& s, size_type pos, size_type n = npos,
               const allocator_type& a = allocator_type()) 
      : base_t(a) 
   {
      if (pos > s.size())
         this->throw_out_of_range();
      else
         this->priv_range_initialize
            (s.begin() + pos, s.begin() + pos + min_value(n, s.size() - pos));
   }

   //! <b>Effects</b>: Constructs a basic_string taking the allocator as parameter,
   //!   and is initialized by a specific number of characters of the s c-string.
   basic_string(const CharT* s, size_type n,
               const allocator_type& a = allocator_type()) 
      : base_t(a) 
   { this->priv_range_initialize(s, s + n); }

   //! <b>Effects</b>: Constructs a basic_string taking the allocator as parameter,
   //!   and is initialized by the null-terminated s c-string.
   basic_string(const CharT* s,
                const allocator_type& a = allocator_type())
      : base_t(a) 
   { this->priv_range_initialize(s, s + Traits::length(s)); }

   //! <b>Effects</b>: Constructs a basic_string taking the allocator as parameter,
   //!   and is initialized by n copies of c.
   basic_string(size_type n, CharT c,
                const allocator_type& a = allocator_type())
      : base_t(a)
   {  
      this->priv_range_initialize(cvalue_iterator(c, n),
                                  cvalue_iterator());
   }

   //! <b>Effects</b>: Constructs a basic_string taking the allocator as parameter,
   //!   and a range of iterators.
   template <class InputIterator>
   basic_string(InputIterator f, InputIterator l,
               const allocator_type& a = allocator_type())
      : base_t(a)
   {
      //Dispatch depending on integer/iterator
      const bool aux_boolean = detail::is_convertible<InputIterator, std::size_t>::value;
      typedef detail::bool_<aux_boolean> Result;
      this->priv_initialize_dispatch(f, l, Result());
   }

   //! <b>Effects</b>: Destroys the basic_string. All used memory is deallocated.
   //!
   //! <b>Throws</b>: Nothing.
   //!
   //! <b>Complexity</b>: Constant.
   ~basic_string() 
   {}
      
   //! <b>Effects</b>: Copy constructs a string.
   //!
   //! <b>Postcondition</b>: x == *this.
   //! 
   //! <b>Complexity</b>: Linear to the elements x contains.
   basic_string& operator=(const basic_string& s)
   {
      if (&s != this) 
         this->assign(s.begin(), s.end());
      return *this;
   }

   //! <b>Effects</b>: Move constructor. Moves mx's resources to *this.
   //!
   //! <b>Throws</b>: If allocator_type's copy constructor throws.
   //! 
   //! <b>Complexity</b>: Constant.
   #ifndef BOOST_INTERPROCESS_RVALUE_REFERENCE
   basic_string& operator=(const detail::moved_object<basic_string>& ms)
   {
      basic_string &s = ms.get();
      if (&s != this){
         this->swap(s);
      }
      return *this;
   }
   #else
   basic_string& operator=(basic_string && ms)
   {
      basic_string &s = ms;
      if (&s != this){
         this->swap(s);
      }
      return *this;
   }
   #endif

   //! <b>Effects</b>: Assignment from a null-terminated c-string.
   basic_string& operator=(const CharT* s) 
   { return this->assign(s, s + Traits::length(s)); }

   //! <b>Effects</b>: Assignment from character.
   basic_string& operator=(CharT c)
   { return this->assign(static_cast<size_type>(1), c); }

   //! <b>Effects</b>: Returns an iterator to the first element contained in the vector.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   iterator begin()
   { return this->priv_addr(); }

   //! <b>Effects</b>: Returns a const_iterator to the first element contained in the vector.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_iterator begin() const
   { return this->priv_addr(); }

   //! <b>Effects</b>: Returns an iterator to the end of the vector.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   iterator end()
   { return this->priv_addr() + this->priv_size(); }

   //! <b>Effects</b>: Returns a const_iterator to the end of the vector.
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_iterator end() const 
   { return this->priv_addr() + this->priv_size(); }  

   //! <b>Effects</b>: Returns a reverse_iterator pointing to the beginning 
   //! of the reversed vector. 
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   reverse_iterator rbegin()             
   { return reverse_iterator(this->priv_addr() + this->priv_size()); }

   //! <b>Effects</b>: Returns a const_reverse_iterator pointing to the beginning 
   //! of the reversed vector. 
   //! 
   //! <b>Throws</b>: Nothing.
   //! 
   //! <b>Complexity</b>: Constant.
   const_reverse_iterator rbegin() const 
   { return const_reverse_iterator(this->priv_addr() + this->priv_size()); }

   //! <b>Effects</b>: Returns a reverse_iterator pointing to the end