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What is a smart pointer and when should I use one?
...nt: When a smart pointer is no longer in use, the memory it points to is deallocated (see also the more detailed definition on Wikipedia).
When should I use one?
In code which involves tracking the ownership of a piece of memory, allocating or de-allocating; the smart pointer often saves you the ne...
How to see top processes sorted by actual memory usage?
...nore the VIRT column, that just tells you how much virtual memory has been allocated, not how much memory the process is using. RES reports how much memory is resident, or currently in ram (as opposed to swapped to disk or never actually allocated in the first place, despite being requested).
But, ...
Hidden Features of MySQL
...le resource when setting these parameters. For example sort_buffer_size is allocated only if MySQL needs to do a sort. Note: be careful not to run out of memory.
If you have many connects established (i.e. a web site without persistent connections) you might improve performance by setting thread_ca...
What is a .snk for?
...lobal Assembly Cache (GAC).
The .snk file contains the public and private tokens for your key. When you want to sign some data (or binary) with that key, a checksum is calculated on the data, which is then encrypted with the private token. The encrypted checksum is then added to the data. Anyone ca...
Passing Data between View Controllers
...h it onto nav stack.
ViewControllerB *viewControllerB = [[ViewControllerB alloc] initWithNib:@"ViewControllerB" bundle:nil];
viewControllerB.isSomethingEnabled = YES;
[self pushViewController:viewControllerB animated:YES];
This will set isSomethingEnabled in ViewControllerB to BOOL value YES.
P...
Is there a way to iterate over a range of integers?
...
Yes runtime.makeslice is clever enough not to allocate any memory if you ask for zero size allocation. However the above still calls it, and according to your benchmark does take 10nS longer on my machine.
– Nick Craig-Wood
Feb 23 ...
Memory management in Qt?
...someButton = new QPushButton; and QPushButton someButton;. The former will allocate the object on the heap, whereas the latter will allocate it on the stack. There's no difference between QPushButton *someButton = new QPushButton(); and QPushButton someButton = new QPushButton;, both of them will ca...
What is the difference between ${var}, “$var”, and “${var}” in the Bash shell?
...happen in a particular order, and some have specific use cases.
Braces as Token Delimiters
The ${var} syntax is primarily used for delimiting ambiguous tokens. For example, consider the following:
$ var1=foo; var2=bar; var12=12
$ echo $var12
12
$ echo ${var1}2
foo2
Braces in Array Expansions
T...
#ifdef vs #if - which is better/safer as a method for enabling/disabling compilation of particular s
...rather than 0/1 in your #define, and because the value is a single lexical token, it's the one time you don't need parentheses around it.
#define DEBUG_ENABLED true
instead of
#define DEBUG_ENABLED (1)
share
...
'size_t' vs 'container::size_type'
...
The standard containers define size_type as a typedef to Allocator::size_type (Allocator is a template parameter), which for std::allocator<T>::size_type is typically defined to be size_t (or a compatible type). So for the standard case, they are the same.
However, if you us...