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Why is address zero used for the null pointer?
..., because it means freeing the pointer again isn't dangerous; when I call malloc it returns a pointer with the value zero if it can't get me memory; I use if (p != 0) all the time to make sure passed pointers are valid, etc.
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Dictionary vs Object - which is more efficient and why?
...e, you are incurring additional overhead because of e.g. additional memory allocations and code execution (e.g. of the __init__ method).
In your code, if o is an Obj instance, o.attr is equivalent to o.__dict__['attr'] with a small amount of extra overhead.
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Is there a reason that Swift array assignment is inconsistent (neither a reference nor a deep copy)?
...ds to change the size of a. In particular, it never needs to do any memory allocation. Regardless of the value of i, this is a lightweight operation. If you imagine that under the hood a is a pointer, it can be a constant pointer.
The second line may be much more complicated. Depending on the value...
How to perform Callbacks in Objective-C
...ts delegate, then there would be a retain cycle. It's a good idea in the dealloc method of a class that that has a MyClass instance and is its delegate to clear that delegate reference since it's a weak back pointer. Otherwise if something is keeping the MyClass instance alive, you'll have a danglin...
Appending a vector to a vector [duplicate]
... = orig;
std::copy(v.begin(), v.end(), std::back_inserter(v));
// std::bad_alloc exception is generated
// GOOD, but I can't guarantee it will work with any STL:
v = orig;
v.reserve(v.size()*2);
v.insert(v.end(), v.begin(), v.end());
// Now v contains: { "first", "second", "first", "second" }
// G...
Find the Smallest Integer Not in a List
...a single entry with a value greater than the number of entries that can be allocated into the array. If the question did not specify 'very long', the answer is elegant, even if it destroys the input. The time-space trade off is very apparent in this problem, and a O(N) solution may not be possible...
Types in MySQL: BigInt(20) vs Int(20)
...111000 (length 39 characters)
If you have INT(20) for system this means allocate in memory minimum 20 bits. But if you'll insert value that bigger than 2^20, it will be stored successfully, only if it's less then INT(32) -> 2147483647 (or 2 * INT(32) -> 4294967295 for UNSIGNED)
Example:
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When should I use std::thread::detach?
...'s a situation when using detach would be a less evil alternative to, say, allocating thread object with dynamic storage duration and then purposely leaking it.
#include <LegacyApi.hpp>
#include <thread>
auto LegacyApiThreadEntry(void)
{
auto result{NastyBlockingFunction()};
//...
Append an object to a list in R in amortized constant time, O(1)?
... single operation occasionally takes much longer than normal (e.g. if a preallocated buffer is exhausted and occasionally requires resizing to a larger buffer size), as long as the long-term average performance is constant time, we'll still call it O(1).
For comparison, I will also describe "linear...
Best practices: throwing exceptions from properties
...t won't; it could easily be calling code that does. Even the simple act of allocating a new object (like a string) could result in exceptions. You should always write your code defensively and expect exceptions from anything you invoke.
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