set::get_allocator
傳回用來配置器物件的複製建構這個集合。
allocator_type get_allocator( ) const;
傳回值
集合是的配置器處理記憶體,是樣板參數的 Allocator。
如需 Allocator,請參閱 set 類別 主題的 < 備註 > 一節。
備註
集合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
// set_get_allocator.cpp
// compile with: /EHsc
#include <set>
#include <iostream>
int main( )
{
using namespace std;
set <int>::allocator_type s1_Alloc;
set <int>::allocator_type s2_Alloc;
set <double>::allocator_type s3_Alloc;
set <int>::allocator_type s4_Alloc;
// The following lines declare objects
// that use the default allocator.
set <int> s1;
set <int, allocator<int> > s2;
set <double, allocator<double> > s3;
s1_Alloc = s1.get_allocator( );
s2_Alloc = s2.get_allocator( );
s3_Alloc = s3.get_allocator( );
cout << "The number of integers that can be allocated"
<< endl << "before free memory is exhausted: "
<< s2.max_size( ) << "." << endl;
cout << "\nThe number of doubles that can be allocated"
<< endl << "before free memory is exhausted: "
<< s3.max_size( ) << "." << endl;
// The following line creates a set s4
// with the allocator of multiset s1.
set <int> s4( less<int>( ), s1_Alloc );
s4_Alloc = s4.get_allocator( );
// Two allocators are interchangeable if
// storage allocated from each can be
// deallocated by the other
if( s1_Alloc == s4_Alloc )
{
cout << "\nThe allocators are interchangeable."
<< endl;
}
else
{
cout << "\nThe 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: 1073741823.
The number of doubles that can be allocated
before free memory is exhausted: 536870911.
The allocators are interchangeable.
需求
標頭: <set>
命名空間: std