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Objective-C ARC: strong vs retain and weak vs assign
...on error to use assign for an object. You have to use either weak or unsafe_unretained (which is unsafe, obviously) if you don't want to retain the property.
– cobbal
Jan 19 '12 at 15:07
...
How to find out which package version is loaded in R?
...plish that.
> sessionInfo()
R version 2.15.0 (2012-03-30)
Platform: x86_64-pc-linux-gnu (64-bit)
locale:
[1] LC_CTYPE=en_US.UTF-8 LC_NUMERIC=C LC_TIME=en_US.UTF-8 LC_COLLATE=en_US.UTF-8
[5] LC_MONETARY=en_US.UTF-8 LC_MESSAGES=en_US.UTF-8 LC_PAPER=C ...
Macro vs Function in C
... int numButtons;
};
struct webpage
{
int numButtons;
};
#define num_button_holes(shirt) ((shirt).numButtons * 4)
struct webpage page;
page.numButtons = 2;
num_button_holes(page) -> 8
Finally, macros can be difficult to debug, producing weird syntax errors or runtime errors that you ha...
How to create the most compact mapping n → isprime(n) up to a limit N?
...ode sample (which I'm trying to understand)
– Freedom_Ben
Aug 8 '14 at 4:08
6
...
get and set in TypeScript
...etter/setter syntax that is like ActionScript3.
class foo {
private _bar: boolean = false;
get bar(): boolean {
return this._bar;
}
set bar(value: boolean) {
this._bar = value;
}
}
That will produce this JavaScript, using the ECMAScript 5 Object.definePropert...
Java: parse int value from a char
...
System.out.println(c & 0b1111); // => '5' & 0b1111 => 0b0011_0101 & 0b0000_1111 => 5
// '0' & 0b1111 => 0b0011_0000 & 0b0000_1111 => 0
// '1' & 0b1111 => 0b0011_0001 & 0b0000_1111 => 1
// '2' & 0b1111 => 0b0011_0010 & 0b0000_1111 => 2
...
How can you encode a string to Base64 in JavaScript?
...ation for Unicode strings: developer.mozilla.org/En/DOM/Window.btoa#Unicode_Strings btoa and atob only work properly for ASCII based strings. As an American, you probably won't notice a difference ... but the first time you use an accented character, your code will break.
– Da...
Traverse a list in reverse order in Python
...
You can do:
for item in my_list[::-1]:
print item
(Or whatever you want to do in the for loop.)
The [::-1] slice reverses the list in the for loop (but won't actually modify your list "permanently").
...
How to achieve function overloading in C?
...rt for function overloading (not operators), thanks to the addition of the _Generic keyword in C11. (supported in GCC since version 4.9)
(Overloading isn't truly "built-in" in the fashion shown in the question, but it's dead easy to implement something that works like that.)
_Generic is a compile-...
How can I represent an 'Enum' in Python?
...34. Code is not perfectly compatible between py2 and py3, e.g. you'll need __order__ in python 2).
To use enum34, do $ pip install enum34
To use aenum, do $ pip install aenum
Installing enum (no numbers) will install a completely different and incompatible version.
from enum import Enum #...