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iOS: Convert UTC NSDate to local Timezone
...eIntervalSince1970:seconds];
NSDateFormatter* df_utc = [[[NSDateFormatter alloc] init] autorelease];
[df_utc setTimeZone:[NSTimeZone timeZoneWithName:@"UTC"]];
[df_utc setDateFormat:@"yyyy.MM.dd G 'at' HH:mm:ss zzz"];
NSDateFormatter* df_local = [[[NSDateFormatter alloc] init] autorelease];
[df_lo...
How do I change the title of the “back” button on a Navigation Bar
...er statement.
UIBarButtonItem *newBackButton =
[[UIBarButtonItem alloc] initWithTitle:@"NewTitle"
style:UIBarButtonItemStyleBordered
target:nil
action:nil];
[[self na...
Is there a performance impact when calling ToList()?
...to store the elements of the list. Arrays cannot be extended once they are allocated so List<T> will use an over-sized array to store the elements of the list. When the List<T> grows beyond the size the underlying array a new array has to be allocated and the contents of the old array ha...
Adding values to a C# array
...might be concerned about performance.
The most efficient method is likely allocating a new array and then using Array.Copy or Array.CopyTo. This is not hard if you just want to add an item to the end of the list:
public static T[] Add<T>(this T[] target, T item)
{
if (target == null)
...
Creating an instance of class
...
Allocates some dynamic memory from the free store, and creates an object in that memory using its default constructor. You never delete it, so the memory is leaked.
Does exactly the same as 1; in the case of user-defined type...
C libcurl get output into a string
...; len} to the callback function and grows that buffer on each call using realloc().
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <curl/curl.h>
struct string {
char *ptr;
size_t len;
};
void init_string(struct string *s) {
s->len = 0;
s->...
Why is the gets function so dangerous that it should not be used?
...out, often messing up the return stack (a Stack Overflow) if the buffer is allocated on the stack, or trampling over the control information if the buffer is dynamically allocated, or copying data over other precious global (or module) variables if the buffer is statically allocated. None of these ...
What is the use of ByteBuffer in Java? [closed]
... empty ByteBuffer with a 10 byte capacity
ByteBuffer bbuf = ByteBuffer.allocate(10);
// Get the buffer's capacity
int capacity = bbuf.capacity(); // 10
// Use the absolute put(int, byte).
// This method does not affect the position.
bbuf.put(0, (byte)0xFF); // position=0
...
What are the best Haskell libraries to operationalize a program? [closed]
...gs) has been something I've done in the past.
$ ./A +RTS -s
64,952 bytes allocated in the heap
1 MB total memory in use
%GC time 0.0% (6.1% elapsed)
Productivity 100.0% of total user, 0.0% of total elapsed
You can get this in machine-readable format too:
$ ./A +RTS -t --machine-readabl...
What are all the common undefined behaviours that a C++ programmer should know about? [closed]
...
Dereferencing a NULL pointer
Dereferencing a pointer returned by a "new" allocation of size zero
Using pointers to objects whose lifetime has ended (for instance, stack allocated objects or deleted objects)
Dereferencing a pointer that has not yet been definitely initialized
Performing pointer ar...