hash_multiset::get_allocator
备注
此 API 已过时。另一种方法是 unordered_multiset Class。
返回用于的分配器对象的复制构造 hash_multiset。
Allocator get_allocator( ) const;
返回值
hash_multiset 使用的分配器管理内存,是选件类的模板参数 Allocator。
有关 Allocator的更多信息,请参见 hash_multiset Class 主题的"备注"节。
备注
hash_multiset 选件类的分配器指定选件类如何管理存储。 默认分配程序提供了 STL 容器选件类对于大多数编程的需要就足够了。 编写和使用您的分配器选件类是高级 C++ 主题。
在 Visual C++ .NET 2003 中,<hash_map> 和 <hash_set> 标头文件的成员中不再标准,命名空间,而是将 stdext 命名空间。 有关更多信息,请参见 stdext 命名空间。
示例
// hash_multiset_get_allocator.cpp
// compile with: /EHsc
#include <hash_set>
#include <iostream>
int main( )
{
using namespace std;
using namespace stdext;
// The following lines declare objects
// that use the default allocator.
hash_multiset <int, hash_compare <int, less<int> > > hms1;
hash_multiset <int, hash_compare <int, greater<int> > > hms2;
hash_multiset <double, hash_compare <double,
less<double> >, allocator<double> > hms3;
hash_multiset <int, hash_compare <int,
greater<int> > >::allocator_type hms2_Alloc;
hash_multiset <double>::allocator_type hms3_Alloc;
hms2_Alloc = hms2.get_allocator( );
cout << "The number of integers that can be allocated"
<< endl << "before free memory is exhausted: "
<< hms1.max_size( ) << "." << endl;
cout << "The number of doubles that can be allocated"
<< endl << "before free memory is exhausted: "
<< hms3.max_size( ) << "." << endl;
// The following lines create a hash_multiset hms4
// with the allocator of hash_multiset hms1.
hash_multiset <int>::allocator_type hms4_Alloc;
hash_multiset <int> hms4;
hms4_Alloc = hms2.get_allocator( );
// Two allocators are interchangeable if
// storage allocated from each can be
// deallocated by the other
if( hms2_Alloc == hms4_Alloc )
{
cout << "The allocators are interchangeable."
<< endl;
}
else
{
cout << "The allocators are not interchangeable."
<< endl;
}
}
示例输出
下面的输出是针对 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.
要求
标头: <hash_set>
命名空间: stdext