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Swift: Testing optionals for nil
... : NSString?
if xyz {
// Do something using `xyz`.
}
This produces an error:
does not conform to protocol 'BooleanType.Protocol'
You have to use one of these forms:
if xyz != nil {
// Do something using `xyz`.
}
if let xy = xyz {
// Do something using `xy`.
}
...
Symbolic links and synced folders in Vagrant
...ountered this same issue: on OS X, I got the symlink has no referent rsync error. I was personally able to solve it by adding particular rsync args to my vagrantfile:
config.vm.synced_folder ".", "/var/www", type: "rsync", rsync__args: ["--verbose", "--archive", "--delete", "-z"]
I also opene...
Installing older version of R package
I am trying to use Rpy2 and ggplot2 but I get an error. After some searching for the error online, I found that the error occurs because there are changes in the ggplot2 package that are not yet reflected in Rpy2 (for example, see this post (Edit: Link is now dead)).
...
How to define an empty object in PHP
...ject from empty value
This could be a problem if your configuration (see error reporting level) shows this warning to the browser. This is another entire topic, but a quick and dirty approach could be using the error control operator (@) to ignore the warning:
$oVal = new stdClass();
@$oVal->k...
Setting the MySQL root user password on OS X
...lowing these steps. When I tried to login again with my new password I get ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
– Þaw
Mar 17 '19 at 12:36
...
How do I modify fields inside the new PostgreSQL JSON datatype?
...r the JSON object when the key is not used. If it's used, it will raise an error:
SELECT jsonb_insert('{"a":[null,{"b":[1]}]}', '{a,1,c}', jsonb '[2]')
-- will yield jsonb '{"a":[null,{"b":[1],"c":[2]}]}', but
SELECT jsonb_insert('{"a":[null,{"b":[1]}]}', '{a,1,b}', jsonb '[2]')
-- will raise SQLSTA...
A JRE or JDK must be available in order to run Eclipse. No JVM was found after searching the followi
...re and has open before without a problem. Now I keep getting the following error message:
27 Answers
...
When is TCP option SO_LINGER (0) required?
...is a bad solution as it causes the TCP connection to be terminated with an error.
Instead, design your application protocol so the connection termination is always initiated from the client side. If the client always knows when it has read all remaining data it can initiate the termination sequence...
Can I see changes before I save my file in Vim?
...
@Dergachev I get the error fatal: bad flag '-' used after filename when I run :w !git diff % -.
– Grayscale
Jul 26 '18 at 3:08
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How to save and load cookies using Python + Selenium WebDriver
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I'm getting "pickle protocol must be <= 2" error. Using the pickle code you posted. What does this mean? Is it referring to the arguments?
– Aaron Hiniker
Feb 25 '13 at 0:50
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