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Is the practice of returning a C++ reference variable evil?
...
return i; // DON'T DO THIS.
}
That is all sorts of evil. The stack-allocated i will go away and you are referring to nothing. This is also evil:
int& getInt() {
int* i = new int;
return *i; // DON'T DO THIS.
}
Because now the client has to eventually do the strange:
int&...
std::function vs template
...pe-erasure magic for the storage. Generally, this implies a dynamic memory allocation (by default through a call to new). It's well known that this is a quite costly operation.
The standard (20.8.11.2.1/5) encorages implementations to avoid the dynamic memory allocation for small objects which, tha...
Is there a difference between YES/NO,TRUE/FALSE and true/false in objective-c?
...
[[NSObject]alloc]init] does not equal TRUE or YES. So testing for object initialization with if ([[NSObject]alloc]init]==TRUE) will fail. I've never been comfortable with a Language defining a singular "true" value when in fact any non ...
What is the overhead of creating a new HttpClient per call in a WebAPI client?
... new HttpClientHandler(); //never dispose this
HttpClient GetClient(string token)
{
//client code can dispose these HttpClient instances
return new HttpClient(_sharedHandler, disposeHandler: false)
{
DefaultRequestHeaders =
{
Authorization = new Authen...
Why aren't superclass __init__ methods automatically invoked?
...ar (it is called during the creation of a new object, after that object is allocated, to set member variables on the new object), and is almost always the place to implement functionality that in other languages you would put in a constructor. So just call it a constructor!
– B...
Convert NSDate to NSString
...
How about...
NSDateFormatter *formatter = [[NSDateFormatter alloc] init];
[formatter setDateFormat:@"yyyy"];
//Optionally for time zone conversions
[formatter setTimeZone:[NSTimeZone timeZoneWithName:@"..."]];
NSString *stringFromDate = [formatter stringFromDate:myNSDateInstance];
...
Rails params explained?
... seeing that in rails4. For instance, {"_method"=>"put", "authenticity_token"=>"gubHya6uQrQLjPRXhOC0RUuCRdn7NFr6CeKrbRfBSHI=", "ripe"=>"true", "action"=>"update", "controller"=>"apples", "id"=>"4"}. Forgive me if I'm wrong, I'm a rails beginner. According to your note, I should ...
When is it right for a constructor to throw an exception?
...and Foo's constructor throws, the language WILL reclaim the memory. If you allocate memory in a constructor and provide no means for releasing it other than the destructor, then the language won't reclaim it if you throw later in the cnostructor. But then, you should have immediately wrapped every a...
What is the default height of UITableViewCell?
...
If you want to calculate this on the fly, just allocate a dummy table cell and read off its height
UITableViewCell *cell = [[UITableViewCell alloc] initWithStyle:UITableViewCellStyleDefault reuseIdentifier:@"Cell"];
int height = cell.frame.size.height ;
This way you de...
How to Rotate a UIImage 90 degrees?
...eImage = [UIImage imageNamed:imgname];
UIImage * portraitImage = [[UIImage alloc] initWithCGImage: landscapeImage.CGImage
scale: 1.0
orientation: UIImageOrientationRight];
Note: As Brainware said th...