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Polymorphism in C++
...rtual Base& operator+=(int) = 0; };
struct X : Base
{
X(int n) : n_(n) { }
X& operator+=(int n) { n_ += n; return *this; }
int n_;
};
struct Y : Base
{
Y(double n) : n_(n) { }
Y& operator+=(int n) { n_ += n; return *this; }
double n_;
};
void f(Base& x) { x...
map function for objects (instead of arrays)
... of obj1 sit on the 'prototype' of obj2
console.log(obj2) // Prints: obj2.__proto__ = { 'a': 1, 'b': 2, 'c': 3}
console.log(Object.keys(obj2)); // Prints: an empty Array.
for (key in obj2) {
console.log(key); // Prints: 'a', 'b', 'c'
}
jsbin
However, please do me a favor and av...
Understanding slice notation
...asic sequences don't support them.
>>> class slicee:
... def __getitem__(self, item):
... return repr(item)
...
>>> slicee()[0, 1:2, ::5, ...]
'(0, slice(1, 2, None), slice(None, None, 5), Ellipsis)'
...
What’s the best way to check if a file exists in C++? (cross platform)
...turns "true" on non-existent files on network shares: "\\machine\share\this_file_doesnt_exist" => true. Last time I checked was on boost 1.33, use caution...
– rlerallut
Nov 6 '08 at 12:54
...
Can I find events bound on an element with jQuery?
...
In modern versions of jQuery, you would use the $._data method to find any events attached by jQuery to the element in question. Note, this is an internal-use only method:
// Bind up a couple of event handlers
$("#foo").on({
click: function(){ alert("Hello") },
mous...
Always pass weak reference of self into block in ARC?
...olve by making an explicitly weak reference to self for the block to use:
__weak MyObject *weakSelf = self;
[self setMyBlock:^(id obj, NSUInteger idx, BOOL *stop) {
[weakSelf doSomethingWithObj:obj];
}];
But this should not be the default pattern you follow when dealing with blocks that ca...
Maven fails to find local artifact
...Maven repo tracks where artifacts originally came from using a file named "_maven.repositories" in the artifact directory. After removing it, the build worked. This answer fixed the problem for me.
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How do I read from parameters.yml in a controller in symfony2?
...and then - the needed parameter.
$this->container->getParameter('api_user');
This documentation chapter explains it.
While $this->get() method in a controller will load a service (doc)
In Symfony 2.7 and newer versions, to get a parameter in a controller you can use the following:
$th...
Play a Sound with Python [duplicate]
...t's built in
import winsound
winsound.PlaySound('sound.wav', winsound.SND_FILENAME)
You should be able to use ossaudiodev for linux:
from wave import open as waveOpen
from ossaudiodev import open as ossOpen
s = waveOpen('tada.wav','rb')
(nc,sw,fr,nf,comptype, compname) = s.getparams( )
dsp = os...
Specifying an Index (Non-Unique Key) Using JPA
...Table;
@Entity
@Table(name = "region",
indexes = {@Index(name = "my_index_name", columnList="iso_code", unique = true),
@Index(name = "my_index_name2", columnList="name", unique = false)})
public class Region{
@Column(name = "iso_code", nullable = false)
priva...