map::get_allocator

傳回用來配置器物件的複製建構對應。

allocator_type get_allocator( ) const;

傳回值

使用對應的配置器。

備註

對應類別的配置器指定類別如何處理儲存區。 預設配置器提供 STL 容器類別中大部分的程式設計需要即可。 撰寫和使用的配置器類別是進階 C++ 主題。

範例

// map_get_allocator.cpp
// compile with: /EHsc
#include <map>
#include <iostream>

int main( )
{
   using namespace std;
   map <int, int>::allocator_type m1_Alloc;
   map <int, int>::allocator_type m2_Alloc;
   map <int, double>::allocator_type m3_Alloc;
   map <int, int>::allocator_type m4_Alloc;

   // The following lines declare objects
   // that use the default allocator.
   map <int, int> m1;
   map <int, int, allocator<int> > m2;
   map <int, double, allocator<double> > m3;

   m1_Alloc = m1.get_allocator( );
   m2_Alloc = m2.get_allocator( );
   m3_Alloc = m3.get_allocator( );

   cout << "The number of integers that can be allocated\n"
        << "before free memory is exhausted: "
        << m2.max_size( ) << ".\n" << endl;

   cout << "The number of doubles that can be allocated\n"
        << "before free memory is exhausted: "
        << m3.max_size( ) <<  ".\n" << endl;

   // The following line creates a map m4
   // with the allocator of map m1.
   map <int, int> m4( less<int>( ), m1_Alloc );

   m4_Alloc = m4.get_allocator( );

   // Two allocators are interchangeable if
   // storage allocated from each can be
   // deallocated with the other
   if( m1_Alloc == m4_Alloc )   
   {
      cout << "The allocators are interchangeable." << endl;
   }
   else   
   {
      cout << "The allocators are not interchangeable." << endl;
   }
}

範例輸出

以下輸出(x86)。

The number of integers that can be allocated
before free memory is exhausted: 536870911.

The number of doubles that can be allocated
before free memory is exhausted: 268435455.

The allocators are interchangeable.

需求

標頭：<map>

命名空間: std

請參閱

參考

map 類別

標準樣板程式庫