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make_unique and perfect forwarding
...ith its use, in which case no function is exception safe. Consider void f( int *, int* ){}, clearly offers the no throw guarantee, but by your line of reasoning it is not exception safe, as it can be misused. Worse, void f( int, int ) {} is not exception safe either!: typedef unique_ptr<int> u...
Tab key == 4 spaces and auto-indent after curly braces in Vim
How do I make vi - Vim never use tabs (converting spaces to tabs, bad!), makes the tab key == 4 spaces, and automatically indent code after curly brace blocks like Emacs does?
...
Check if UIColor is dark or bright?
...l? {
let originalCGColor = self.cgColor
// Now we need to convert it to the RGB colorspace. UIColor.white / UIColor.black are greyscale and not RGB.
// If you don't do this then you will crash when accessing components index 2 below when evaluating greyscale colors.
...
What exactly is LLVM?
...u provide the "front end" (parser and lexer) and the "back end" (code that converts LLVM's representation to actual machine code).
LLVM can also act as a JIT compiler - it has support for x86/x86_64 and PPC/PPC64 assembly generation with fast code optimizations aimed for compilation speed.
Unfortu...
warning: implicit declaration of function
... the compiler has not seen a declaration ("prototype") yet.
For example:
int main()
{
fun(2, "21"); /* The compiler has not seen the declaration. */
return 0;
}
int fun(int x, char *p)
{
/* ... */
}
You need to declare your function before main, like this, either directly or ...
How can I hash a password in Java?
...spec).getEncoded();
Base64.Encoder enc = Base64.getEncoder();
System.out.printf("salt: %s%n", enc.encodeToString(salt));
System.out.printf("hash: %s%n", enc.encodeToString(hash));
Here's a utility class that you can use for PBKDF2 password authentication:
import java.security.NoSuchAlgorithmExcep...
Using Linq to get the last N elements of a collection?
...c IEnumerable<T> TakeLast<T>(this IEnumerable<T> source, int N)
{
return source.Skip(Math.Max(0, source.Count() - N));
}
}
A brief note on performance:
Because the call to Count() can cause enumeration of certain data structures, this approach has the risk of cau...
Adding a new SQL column with a default value
...
Try this:
ALTER TABLE table1 ADD COLUMN foo INT DEFAULT 0;
From the documentation that you linked to:
ALTER [ONLINE | OFFLINE] [IGNORE] TABLE tbl_name
alter_specification [, alter_specification] ...
alter_specification:
...
ADD [COLUMN] (col_name colum...
Picking a random element from a set
How do I pick a random element from a set?
I'm particularly interested in picking a random element from a
HashSet or a LinkedHashSet, in Java.
Solutions for other languages are also welcome.
...
What is the simplest and most robust way to get the user's current location on Android?
...d(String provider) {}
public void onStatusChanged(String provider, int status, Bundle extras) {}
};
LocationListener locationListenerNetwork = new LocationListener() {
public void onLocationChanged(Location location) {
timer1.cancel();
locationResult....