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What are the differences between poll and select?
...s, and see if it ever gets fixed.
With poll(), however, the user must allocate an array of pollfd
structures, and pass the number of entries in this array, so there's
no fundamental limit. As Casper notes, fewer systems have poll() than
select, so the latter is more portable. Also, with...
throwing exceptions out of a destructor
...mory for Object go? Where does the memory the object owned go? Is it still allocated (ostensibly because the destructor failed)? Consider also the object was in stack space, so its obviously gone regardless.
Then consider this case
class Object
{
Object2 obj2;
Object3* obj3;
virtual ~Obj...
How to correctly implement custom iterators and const_iterators?
...
You need to edit your answer. Assuming m_data was allocated with m_size elements you get Undefined Behavior: m_data[m_size] is UB. You can simply fix it by replacing it with m_data+m_size. For reverse iterators, both m_data[-1] and m_data-1 are incorrect (UB). To fix reverse...
What's the difference between SoftReference and WeakReference in Java?
...object is phantomly referenced after it has been finalized, but before its allocated memory has been reclaimed.
Source
Analogy: Assume a JVM is a kingdom, Object is a king of the kingdom, and GC is an attacker of the kingdom who tries to kill the king(object).
When King is Strong, GC can not k...
How does PHP 'foreach' actually work?
...ns is that 'FYFY' has the same hash as the removed element 'EzFY', and the allocator happens to reuse the same memory location to store the element. So foreach ends up directly jumping to the newly inserted element, thus short-cutting the loop.
Substituting the iterated entity during the loop
One ...
Use numpy array in shared memory for multiprocessing
... size of the Array. Think of it as a shared block of memory that had to be allocated before child processes are started. You don't need to use all the memory e.g., you could pass count to numpy.frombuffer(). You could try to do it on a lower level using mmap or something like posix_ipc directly to i...
Should 'using' directives be inside or outside the namespace?
...ler errors. However, it is unclear which version of the Guid type is being allocated. If the using directive is moved inside of the namespace, as shown below, a compiler error will occur:
namespace Microsoft.Sample
{
using Guid = System.Guid;
public class Guid
{
public Guid(stri...
Are there disadvantages to using a generic varchar(255) for all text-based fields?
...
It's good practice to allocate only a little over what you need. Phone numbers would never go this large.
One reason is that unless you validate against large entries, no doubt someone will use all there is. Then you might run out of space in...
In a storyboard, how do I make a custom cell for use with multiple controllers?
...k at the class of the cell, as defined in the cell's nib. Call [[CellClass alloc] initWithCoder:].
The -initWithCoder: method goes through and adds subviews and sets properties that were defined in the nib. (IBOutlets probably get hooked up here as well, though I haven't tested that; it may happen i...
Understanding Canvas and Surface concepts
...seen.
A Bitmap is just an interface to some pixel data. The pixels may be allocated by Bitmap itself when you are directly creating one, or it may be pointing to pixels it doesn't own such as what internally happens to hook a Canvas up to a Surface for drawing. (A Bitmap is created and pointed to ...