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Create singleton using GCD's dispatch_once in Objective-C
...er here: instancetype
+ (instancetype)sharedInstance
{
static dispatch_once_t once;
static id sharedInstance;
dispatch_once(&once, ^
{
sharedInstance = [self new];
});
return sharedInstance;
}
+ (Class*)sharedInstance
{
static dispatch_once_t once;
...
Is arr.__len__() the preferred way to get the length of an array in Python?
...
my_list = [1,2,3,4,5]
len(my_list)
# 5
The same works for tuples:
my_tuple = (1,2,3,4,5)
len(my_tuple)
# 5
And strings, which are really just arrays of characters:
my_string = 'hello world'
len(my_string)
# 11
It was in...
Socket.IO - how do I get a list of connected sockets/clients?
...lients('room');
anymore. Instead you can use the following
var clients_in_the_room = io.sockets.adapter.rooms[roomId];
for (var clientId in clients_in_the_room ) {
console.log('client: %s', clientId); //Seeing is believing
var client_socket = io.sockets.connected[clientId];//Do whatever y...
C++ display stack trace on exception
...
On the home page of StackTrace, I see throw stack_runtime_error. Am I correct in deducing that this lib only works for exceptions derived from that class, and not for std::exception or exceptions from third-party libraries?
– Thomas
No...
Python 2.7: Print to File
...If you want to use the print function in Python 2, you have to import from __future__:
from __future__ import print_function
But you can have the same effect without using the function, too:
print >>f1, 'This is a test'
...
How to install Java SDK on CentOS?
...is, the lastest available version may be different.
java-1.7.0-openjdk.x86_64
The above package alone will only install JRE. To also install javac and JDK, the following command will do the trick:
$ yum install java-1.7.0-openjdk*
These packages will be installing (as well as their dependencie...
Django rest framework nested self-referential objects
...('parentCategory', 'name', 'description', 'subcategories')
def get_related_field(self, model_field):
# Handles initializing the `subcategories` field
return CategorySerializer()
Actually, as you've noted the above isn't quite right.
This is a bit of a hack, but y...
TypeScript static classes
...with javascript so it doesn't make much sense
– Simon_Weaver
May 23 '14 at 1:59
4
@Simon_Weaver Y...
get current url in twig template?
...
{{ path(app.request.attributes.get('_route'),
app.request.attributes.get('_route_params')) }}
If you want to read it into a view variable:
{% set currentPath = path(app.request.attributes.get('_route'),
app.request.attributes.get(...
Get Image size WITHOUT loading image into memory
... data (or call the load method).
Digging deeper, we see that .open calls _open which is a image-format specific overload. Each of the implementations to _open can be found in a new file, eg. .jpeg files are in JpegImagePlugin.py. Let's look at that one in depth.
Here things seem to get a bit tric...