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How to sort an array by a date property
...ave hit production performance issues specifically for that reason. Do not allocate memory (and GC) inside a sort method.
– MikeMurko
Jul 13 '19 at 5:26
4
...
UILabel with text of two different colors
...ike this:
NSMutableAttributedString *text =
[[NSMutableAttributedString alloc]
initWithAttributedString: label.attributedText];
[text addAttribute:NSForegroundColorAttributeName
value:[UIColor redColor]
range:NSMakeRange(10, 1)];
[label setAttributedText: text];
...
String literals: Where do they go?
I am interested in where string literals get allocated/stored.
8 Answers
8
...
MySQL - length() vs char_length()
... store 10 characters, which may be more than 10 bytes.
In indexes, it will allocate the maximium length of the field - so if you are using UTF8-mb4, it will allocate 40 bytes for the 10 character field.
share
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...
What does template mean?
...emplate template parameter.
template<template<typename T> class AllocatePolicy>
struct Pool {
void allocate(size_t n) {
int *p = AllocatePolicy<int>::allocate(n);
}
};
// pass the template "allocator" as argument.
template<typename T>
struct allocator { st...
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 should one use std::optional?
...nt(std::string s); //return nullptr if fail
This requires dynamic memory allocation, worrying about ownership, etc. - always prefer one of the other two signatures above.
Another example:
class Contact
{
std::optional<std::string> home_phone;
std::optional<std::string> work...
Virtual Memory Usage from Java under Linux, too much memory used
...is last item is either a file or "anon", which indicates a block of memory allocated via mmap.
Starting from the top, we have
The JVM loader (ie, the program that gets run when you type java). This is very small; all it does is load in the shared libraries where the real JVM code is stored.
A bun...
Core Data: Quickest way to delete all instances of an entity
...ndle the error
}
Objective-C
NSFetchRequest *request = [[NSFetchRequest alloc] initWithEntityName:@"Car"];
NSBatchDeleteRequest *delete = [[NSBatchDeleteRequest alloc] initWithFetchRequest:request];
NSError *deleteError = nil;
[myPersistentStoreCoordinator executeRequest:delete withContext:myCon...
What are the applications of binary trees?
....
Treap - Randomized data structure used in wireless networking and memory allocation.
T-tree - Though most databases use some form of B-tree to store data on the drive, databases which keep all (most) their data in memory often use T-trees to do so.
The reason that binary trees are used more of...