How to allocate memory which is 2^k aligned

[Divick]

Hi,
can somebody help me figure out how can I make write a function
which inturn uses malloc routine to allocate memory which is 2^k
aligned?

The condition is such that there should not be any memory leak and it
should not also waste memory.

Thanks,
Divick

[dasjotre]

dasjotre wrote:
<snip>

sorry, I was beeing lazy ...

template <std::size_t Size, std::size_t Align>
class aligned_str
{
boost::aligned_ storage<Size, Alignaligned_;

public:

void * operator new(std::size_t )
{
typedef aligned_str<Siz e, AllignT;
return malloc(sizeof(T ));
}

void operator delete(void *p)
{
free(p);
}

void * address(){ return aligned_.addres s(); }
};

typedef aligned_str<Siz e, Alignmy_aligned ;
::std::auto_ptr <my_alignedp (new my_aligned);
// and use
p->address();

[Pete Becker]

dasjotre wrote:

Divick wrote:

>>Hi,
can somebody help me figure out how can I make write a function
which inturn uses malloc routine to allocate memory which is 2^k
aligned?

The condition is such that there should not be any memory leak and it
should not also waste memory.

you could try something like

template <std::size_t Size, std::size_t Align>
struct aligned_str
{
boost::aligned_ storage<Size, Alignaligned_;
};

typedef aligned_str<Siz e, Alignmy_aligned ;
my_aligned * p = static_cast<my_ aligned*>(mallo c(sizeof(my_ali gned));
// and use
p->aligned_.addre ss();

I don't think that will work. aligned_storage is basically a union of a
char array of the appropriate size and some other type with suitable
alignment. For TR1 we made it clear that, essentially, the value of
Align must be a value that is the alignment of some type. It doesn't
handle arbitrary alignment values.

--

-- Pete

Author of "The Standard C++ Library Extensions: a Tutorial and Reference."
For more information about this book, see www.petebecker.com/tr1book.