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Why would you use an ivar?
...d by the compiler may involve another C function call to the functions objc_getProperty/objc_setProperty, as these will have to retain/copy/autorelease the objects as needed and further perform spinlocking for atomic properties where necessary. This can easily get very expensive and I'm not talking ...
JavaScript pattern for multiple constructors
... b= 'some default value';
if (typeof(a)==='string')
this._constructInSomeWay(a, b);
else if (a instanceof MyType)
this._constructInSomeOtherWay(a, b);
}
You can also access arguments as an array-like to get any further arguments passed in.
If you need more complex ar...
Given a view, how do I get its viewController?
...nd
This macro avoids category pollution:
#define UIViewParentController(__view) ({ \
UIResponder *__responder = __view; \
while ([__responder isKindOfClass:[UIView class]]) \
__responder = [__responder nextResponder]; \
(UIViewController *)__responder; \
})
...
How to lock orientation during runtime
...
setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_LANDSCAPE);
Called on an activity, will lock it to landscape. Look for the other flags in the ActivityInfo class. You can lock it back to portrait or make it sensor/slider driven.
More info here: http://www....
Why does GCC generate 15-20% faster code if I optimize for size instead of speed?
...ssembly from gcc-4.6.4 -Os (executes in 0.709 secs):
00000000004004d2 <_ZL3addRKiS0_.isra.0>:
4004d2: 8d 04 37 lea eax,[rdi+rsi*1]
4004d5: c3 ret
00000000004004d6 <_ZL4workii>:
4004d6: 41 55 push r13
4...
Reverse colormap in matplotlib
...ly reverse the color order of a given colormap in order to use it with plot_surface.
7 Answers
...
Find which version of package is installed with pip
...hat is the difference between using pip list and doing import X and then X.__version__? Are both the package versions?
– variable
Oct 13 '19 at 4:27
...
How to initialize a private static const map in C++?
...ap>
using namespace std;
struct A{
static map<int,int> create_map()
{
map<int,int> m;
m[1] = 2;
m[3] = 4;
m[5] = 6;
return m;
}
static const map<int,int> myMap;
};
const map<int,int> A:: myMap = ...
How to throw an exception in C?
...m Wikipedia
#include <stdio.h>
#include <setjmp.h>
static jmp_buf buf;
void second(void) {
printf("second\n"); // prints
longjmp(buf,1); // jumps back to where setjmp
// was called - making setjmp now return 1
}
void firs...
How do I perform the SQL Join equivalent in MongoDB?
...ttps://docs.mongodb.org/master/reference/operator/aggregation/lookup/#pipe._S_lookup
From the docs:
{
$lookup:
{
from: <collection to join>,
localField: <field from the input documents>,
foreignField: <field from the documents of the "from" collection>...