Copies objects of a specified value into specified number of elements into an uninitialized destination range.
template<class FwdIt, class Size, class Type>
void uninitialized_fill_n(
ForwardIterator _First,
Size _Count,
const Type& _Val
);
Parameters
_First
A forward iterator addressing the first element in the destination range to be initiated._Count
The number of elements to be initialized._Val
The value to be used to initialize the destination range.
Remarks
This algorithm allows the decoupling of memory allocation from object construction.
The template function effectively executes:
while ( 0 < count-- )
new ( ( void * )&*_First ++ )
iterator_traits<ForwardIterator>::value_type( _Val );
unless the code throws an exception. In that case, all constructed objects are destroyed and the exception is rethrown.
uninitialized_fill_n has two related forms:
For information on how these functions behave, see Checked Iterators.
Example
// memory_uninit_fill_n.cpp
// compile with: /EHsc /W3
#include <memory>
#include <iostream>
using namespace std;
class Integer { // No default constructor
public:
Integer( int x ) : val( x ) {}
int get( ) { return val; }
private:
int val;
};
int main() {
const int N = 10;
Integer val ( 60 );
Integer* Array = ( Integer* ) malloc( N * sizeof( int ) );
uninitialized_fill_n( Array, N, val ); // C4996
int i;
cout << "The uninitialized Array contains: ";
for ( i = 0 ; i < N; i++ )
cout << Array [ i ].get( ) << " ";
}
Output
The uninitialized Array contains: 60 60 60 60 60 60 60 60 60 60
Requirements
Header: <memory>
Namespace: std