allocator::allocate
Allocates a block of memory large enough to store at least some specified number of elements.
pointer allocate(
size_type _Count,
const void* _Hint
);
Parameters
_Count
The number of elements for which sufficient storage is to be allocated._Hint
A const pointer that may assist the allocator object satisfy the request for storage by locating the address of an object allocated prior to the request.
Return Value
A pointer to the allocated object or null if memory was not allocated.
Remarks
The member function allocates storage for an array of count elements of type Type, by calling operator new(_Count). It returns a pointer to the allocated object. The hint argument helps some allocators in improving locality of reference; a valid choice is the address of an object earlier allocated by the same allocator object and not yet deallocated. To supply no hint, use a null pointer argument instead.
Example
// allocator_allocate.cpp
// compile with: /EHsc
#include <memory>
#include <iostream>
#include <vector>
using namespace std;
int main( )
{
allocator<int> v1Alloc;
allocator<int>::pointer v1aPtr;
v1aPtr = v1Alloc.allocate ( 10 );
int i;
for ( i = 0 ; i < 10 ; i++ )
{
v1aPtr[ i ] = i;
}
for ( i = 0 ; i < 10 ; i++ )
{
cout << v1aPtr[ i ] << " ";
}
cout << endl;
v1Alloc.deallocate( v1aPtr, 10 );
}
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Requirements
Header: <memory>
Namespace: std