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Passing references to pointers in C++
...er itself, not the object to which it points. For example, a function that allocates memory and assigns the address of the memory block it allocated to its argument must take a reference to a pointer, or a pointer to pointer:
void myfunc(string*& val)
{
//val is valid even after function call
...
How to print out the method name and line number and conditionally disable NSLog?
...fdef DEBUG
# define ULog(fmt, ...) { UIAlertView *alert = [[UIAlertView alloc] initWithTitle:[NSString stringWithFormat:@"%s\n [Line %d] ", __PRETTY_FUNCTION__, __LINE__] message:[NSString stringWithFormat:fmt, ##__VA_ARGS__] delegate:nil cancelButtonTitle:@"Ok" otherButtonTitles:nil]; [alert sh...
UIActivityViewController crashing on iOS 8 iPads
...image];
UIActivityViewController *controller = [[UIActivityViewController alloc] initWithActivityItems:postItems applicationActivities:nil];
//if iPhone
if (UI_USER_INTERFACE_IDIOM() == UIUserInterfaceIdiomPhone) {
[self presentViewController:controller animated:YES completion:nil];
}
//if iPa...
.NET List Concat vs AddRange
...ed execution, using Concat would likely be faster because it avoids object allocation - Concat doesn't copy anything, it just creates links between the lists so when enumerating and you reach the end of one it transparently takes you to the start of the next!
– Greg Beech
...
Why is an int in OCaml only 31 bits?
...
See the the "representation of integers, tag bits, heap-allocated values" section of https://ocaml.org/learn/tutorials/performance_and_profiling.html for a good description.
The short answer is that it is for performance. When passing an argument to a function it is either passe...
.NET unique object identifier
...utomatically so the information is correct.
Object IDs are 64-bit numbers. Allocation starts from one, so zero is never a valid object ID. A formatter can choose a zero value to represent an object reference whose value is a null reference (Nothing in Visual Basic).
...
Is there a destructor for Java?
...
Nope, no destructors here. The reason is that all Java objects are heap allocated and garbage collected. Without explicit deallocation (i.e. C++'s delete operator) there is no sensible way to implement real destructors.
Java does support finalizers, but they are meant to be used only as a safegu...
How to read the content of a file to a string in C?
... 0, SEEK_END);
length = ftell (f);
fseek (f, 0, SEEK_SET);
buffer = malloc (length);
if (buffer)
{
fread (buffer, 1, length, f);
}
fclose (f);
}
if (buffer)
{
// start to process your data / extract strings here...
}
...
How do I base64 encode (decode) in C?
... *output_length = 4 * ((input_length + 2) / 3);
char *encoded_data = malloc(*output_length);
if (encoded_data == NULL) return NULL;
for (int i = 0, j = 0; i < input_length;) {
uint32_t octet_a = i < input_length ? (unsigned char)data[i++] : 0;
uint32_t octet_b = ...
C++ Lock-free Hazard Pointer（冒险指针） - C/C++ - 清泛网 - 专注C/C++及内核技术
...re(const std::atomic<T *> &target) {
auto pointer = HazardPointer<T>::Alloc();
do {
pointer->target_ = target.load(std::memory_order_acquire);
} while (pointer->target_.load(std::memory_order_acquire) !=
target.load(std::memory_order_acquire));
return Holde...