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Why are these constructs using pre and post-increment undefined behavior?
... concept of undefined behavior, i.e. some language constructs are syntactically valid but you can't predict the behavior when the code is run.
As far as I know, the standard doesn't explicitly say why the concept of undefined behavior exists. In my mind, it's simply because the language designers w...
Migration: Cannot add foreign key constraint
...signed();
$table->string('priority_name');
$table->smallInteger('rank');
$table->text('class');
$table->timestamps('timecreated');
});
Schema::table('priorities', function($table) {
$table->foreign('user_id')->references('id')->on('...
How to make a python, command-line program autocomplete arbitrary things NOT interpreter
...ts, i.e. --help, --verbose and --version. For your purposes, you'll essentially want to customise the values that are put into opts.
Do have a look at the example on the linked page, it's all pretty straightforward.
share
...
Detect when browser receives file download
I have a page that allows the user to download a dynamically-generated file. It takes a long time to generate, so I'd like to show a "waiting" indicator. The problem is, I can't figure out how to detect when the browser has received the file, so I can hide the indicator.
...
Get button click inside UITableViewCell
...ce Builder (IB) in step two. Just make sure your buttons tag is set. You really don't want to mix up your action calling. Either do it through IB or do it explicitly in your code.
– Sententia
Apr 29 '14 at 7:12
...
Proper use of beginBackgroundTaskWithExpirationHandler
...l need to wrap it in a background task. It's also very important that you call endBackgroundTask when you're finished - otherwise the app will be killed after its allotted time has expired.
Mine tend look something like this:
- (void) doUpdate
{
dispatch_async(dispatch_get_global_queue(DISPAT...
How to create has_and_belongs_to_many associations in Factory girl
...
Thank you, most neat of all solutions.
– Mik
May 29 '12 at 19:14
Th...
How do you read a file into a list in Python? [duplicate]
...each line might have. When the with ends, the file will be closed automatically for you. This is true even if an exception is raised inside of it.
2. use of list comprehension
This could be considered inefficient as the file descriptor might not be closed immediately. Could be a potential issue wh...
Getting error: Peer authentication failed for user “postgres”, when trying to get pgsql working with
....conf file (/etc/postgresql/9.1/main/pg_hba.conf*).
This line:
local all postgres peer
Should be:
local all postgres md5
* If you can't find this file, running locate pg_hba.conf should show you where ...
UTF-8 byte[] to String
... You can see in here the java.nio.charset.Charset.availableCharsets() map all the charsets not just the charsets in the StandardCharsets. And if you want to use some other charset and still want to prevent the String constructor from throwing UnsupportedEncodingException you may use java.nio.charse...