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Setting variable to NULL after free
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Setting unused pointers to NULL is a defensive style, protecting against dangling pointer bugs. If a dangling pointer is accessed after it is freed, you may read or overwrite random memory. If a null pointer is accessed, you get an immediate ...
Does order of where clauses matter in SQL?
...le (or clustered index) scan instead of using an index (because the lookup into the full data page to get all other columns just gets too expensive very quickly).
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When should I use the Visitor Design Pattern? [closed]
... Animal { };
(Suppose it is a complex hierarchy with a well-established interface.)
Now we want to add a new operation to the hierarchy, namely we want each animal to make its sound. As far as the hierarchy is this simple, you can do it with straight polymorphism:
class Animal
{ public: virtual...
Any difference between First Class Function and High Order Function
...the language treats functions as values – that you can assign a function into a variable, pass it around etc. Higher-order functions are functions that work on other functions, meaning that they take one or more functions as an argument and can also return a function.
The “higher-order” conce...
scala vs java, performance and memory? [closed]
I am keen to look into Scala, and have one basic question I cant seem to find an answer to:
in general, is there a difference in performance and usage of memory between Scala and Java?
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Easier way to debug a Windows service
...ommand line switch for that purpose?
Couldn't you just do:
public static int Main(string[] args)
{
if (!Environment.UserInteractive)
{
// Startup as service.
}
else
{
// Startup as application
}
}
That would have the "benefit", that you can just start your app via doubleclick...
Difference between Lookup() and Dictionary(Of list())
...t least, I believe the concrete Lookup class is immutable, and the ILookup interface doesn't provide any mutating members. There could be other mutable implementations, of course.)
When you lookup a key which isn't present in a lookup, you get an empty sequence back instead of a KeyNotFoundException...
What does “zend_mm_heap corrupted” mean
...clude <stdio.h>
#include <string.h>
#include <stdlib.h>
int main(void) {
void **mem = malloc(sizeof(char)*3);
void *ptr;
/* read past end */
ptr = (char*) mem[5];
/* write past end */
memcpy(mem[5], "whatever", sizeof("whatever"));
/* free invalid...
Cancellation token in Task constructor: why?
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Passing a CancellationToken into the Task constructor associates it with the task.
Quoting Stephen Toub's answer from MSDN:
This has two primary benefits:
If the token has cancellation requested prior to the Task starting to execute, the Ta...
How does PHP 'foreach' actually work?
...ng over an object, the packed representation that is normally used will be converted to a real dictionary. At that point, iteration of plain objects becomes very similar to iteration of arrays (which is why I'm not discussing plain-object iteration much in here).
So far, so good. Iterating over a d...