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Why are Objective-C delegates usually given the property assign instead of retain?
...wner
If B had retained A, A wouldn't be released, as B owns A, thus A's dealloc would never get called, causing both A and B to leak.
You shouldn't worry about A going away because it owns B and thus gets rid of it in dealloc.
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How to correctly implement custom iterators and const_iterators?
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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...
Is Fortran easier to optimize than C for heavy calculations?
...ers will most likely return that struct in sret form with the caller stack allocating space, passing a pointer to the callee that fills it in. That is several times slower than returning multiple values in registers as a Fortran compiler would. Note that C99 fixed this in the special case of complex...
What are fixtures in programming?
...tate a method with @org.junit.After to release any permanent resources you allocated in setUp
For example, to write several test cases that want to work with different combinations of 12 Swiss Francs, 14 Swiss Francs, and 28 US Dollars, first create a fixture:
public class MoneyTest {
private M...
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...
How do you know when to use fold-left and when to use fold-right?
... // third stack frame
// (I don't remember if the JVM allocates space
// on the stack for the third frame as well)
while List(1,2,3).foldLeft(0)(_ + _) would reduce to:
(((0 + 1) + 2) + 3)
which can be iteratively computed, as done in the implementation of List.
In a str...
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?
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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...
Is pass-by-value a reasonable default in C++11?
... especially around memory management (in the event that the object is heap-allocated)
4 Answers
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