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Use of alloc init instead of new
...ere are a bunch of reasons here: http://macresearch.org/difference-between-alloc-init-and-new
Some selected ones are:
new doesn't support custom initializers (like initWithString)
alloc-init is more explicit than new
General opinion seems to be that you should use whatever you're comfortable wi...
What uses are there for “placement new”?
...
Placement new allows you to construct an object in memory that's already allocated.
You may want to do this for optimization when you need to construct multiple instances of an object, and it is faster not to re-allocate memory each time you need a new instance. Instead, it might be more efficien...
How to allocate aligned memory only using the standard library?
...
Original answer
{
void *mem = malloc(1024+16);
void *ptr = ((char *)mem+16) & ~ 0x0F;
memset_16aligned(ptr, 0, 1024);
free(mem);
}
Fixed answer
{
void *mem = malloc(1024+15);
void *ptr = ((uintptr_t)mem+15) & ~ (uintptr_t)0x0...
What does the “__block” keyword mean?
...and static.[testme] Variables qualified by __block act as if they were in allocated storage and this storage is automatically recovered after last use of said variable. An implementation may choose an optimization where the storage is initially automatic and only "moved" to allocated (heap) storag...
How to hide the “back” button in UINavigationController?
.... I could do something like:
UIViewController *newVC = [[UIViewController alloc] init];
//presumably would do some stuff here to set up the new view controller
newVC.navigationItem.hidesBackButton = YES;
[myNavController pushViewController:newVC animated:YES];
When the code finishes, the view con...
What is The Rule of Three?
... executing the body of the destructor and destroying any automatic objects allocated within the body,
a destructor for class X calls the destructors for X's direct [...] members
[n3126.pdf 12.4 §6]
Managing resources
So when should we declare those special member functions explicitly?
When our cla...
How to resize a VirtualBox vmdk file
...
vmdk's :
Rather fixed size allocation (step 1,2).
Even after expansion, not readily available inside the vmdk's OS (step 3,4,5)
STEPS:
1) convert to ".vdi" first - VBoxManage clonehd v1.vmdk v1.vdi --format vdi
2) expand the size using command-line (R...
How do you add an action to a button programmatically in xcode
...ame = CGRectMake( 10, 80, 100, 30 );
UIButton *button = [[UIButton alloc] initWithFrame: buttonFrame];
[button setTitle: @"My Button" forState: UIControlStateNormal];
[button addTarget:self action:@selector(btnSelected:) forControlEvents:UIControlEventTouchUpInside];
...
Is there a best practice for generating html with javascript
...nce seen in the first method is likely because the result string must be reallocated 200 times, and memory allocations can be slow. After two iterations you have "testingtesting". After three iterations, that string is thrown away and memory with enough room for "testingtestingtesting" is allocate...
C++ new int[0] — will it allocate memory?
... When the value of the expression in a direct-new-declarator is zero, the allocation function is called to allocate an array with no elements.
From 3.7.3.1/2
The effect of dereferencing a pointer returned as a request for zero size is undefined.
Also
Even if the size of the space reques...