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Concurrent vs serial queues in GCD
... running in background thread")
}
let imgURL = URL(string: "https://upload.wikimedia.org/wikipedia/commons/0/07/Huge_ball_at_Vilnius_center.jpg")!
let _ = try! Data(contentsOf: imgURL)
print("\(i) completed downloading")
}
}
}
Task wil...
Why do we not have a virtual constructor in C++?
...) to allocate memory
invoke Derived() with placement new.
OR
create an extra vtable entry for a function that combines dynamic allocation and construction
So - it doesn't seem insurmountable to specify and implement virtual constructors, but the million-dollar question is: how would it be bett...
How to get an enum value from a string value in Java?
...far, should I understand that it's good practice to define an enum and its String value to be exactly the same?
– Kevin Meredith
Feb 12 '14 at 21:24
...
Simple example of threading in C++
...reate a function that you want the thread to execute, eg:
void task1(std::string msg)
{
std::cout << "task1 says: " << msg;
}
Now create the thread object that will ultimately invoke the function above like so:
std::thread t1(task1, "Hello");
(You need to #include <thread>...
Can I mix MySQL APIs in PHP?
...tell me today that they've no problem/errors when mixing mysql_real_escape_string() with what the rest of their code being PDO. Is there something I didn't get here in my time with working with these different APIs? Am I the ignorant one here? This being for the "now deleted" question stackoverflow....
What are the differences between a pointer variable and a reference variable in C++?
..., the lifetime of that object becomes the lifetime of the reference.
std::string s1 = "123";
std::string s2 = "456";
std::string s3_copy = s1 + s2;
const std::string& s3_reference = s1 + s2;
In this example s3_copy copies the temporary object that is a result of the concatenation. Whereas s3...
How to implement Enums in Ruby?
...e when you want to enhance readability without littering code with literal strings.
postal_code[:minnesota] = "MN"
postal_code[:new_york] = "NY"
Constants are appropriate when you have an underlying value that is important. Just declare a module to hold your constants and then declare the constan...
What is the difference between Python's list methods append and extend?
...st.
my_list.append(object)
Whatever the object is, whether a number, a string, another list, or something else, it gets added onto the end of my_list as a single entry on the list.
>>> my_list
['foo', 'bar']
>>> my_list.append('baz')
>>> my_list
['foo', 'bar', 'baz']...
What are the best practices for SQLite on Android?
... new AtomicInteger(0);
public DBSQLiteOpenHelper(Context context, String name, int version, DatabaseManager databaseManager) {
super(context, name, null, version);
this.databaseManager = databaseManager;
}
public void addConnection(){
cou...
What's the best way to validate an XML file against an XSD file?
...on:" + e);
} catch (IOException e) {}
The schema factory constant is the string http://www.w3.org/2001/XMLSchema which defines XSDs. The above code validates a WAR deployment descriptor against the URL http://java.sun.com/xml/ns/j2ee/web-app_2_4.xsd but you could just as easily validate against a ...