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Why does this loop produce “warning: iteration 3u invokes undefined behavior” and output more than 4
...s no such thing as "unsigned integer overflow") means undefined behaviour. And this means anything can happen, and discussing why does it happen under the rules of C++ doesn't make sense.
C++11 draft N3337: §5.4:1
If during the evaluation of an expression, the result is not mathematically de...
How to prevent ifelse() from turning Date objects into numeric objects
... to manipulate a date vector. I expected the result to be of class Date , and was surprised to get a numeric vector instead. Here is an example:
...
How can I merge two commits into one if I already started rebase?
...base todo list, that is into a commit on a previous line. Changing the command on your todo list’s very first line to squash will always produce this error as there is nothing for the first commit to squash into.
The Fix
First get back to where you started with
$ git rebase --abort
Say your h...
Type erasure techniques
... erasure techniques in C++ are done with function pointers (for behaviour) and void* (for data). The "different" methods simply differ in the way they add semantic sugar. Virtual functions, e.g., are just semantic sugar for
struct Class {
struct vtable {
void (*dtor)(Class*);
vo...
Git commit with no commit message
...providing a meaningful commit message is part of good development practice and good repository stewardship. The first line of the commit message is used all over the place within git; for more, read "A Note About Git Commit Messages".
If you open Terminal.app, cd to your project directory, and git ...
What do I need to do to get Internet Explorer 8 to accept a self signed certificate?
...Options.
Select Security➞Trusted sites➞Sites.
Confirm the URL matches, and click “Add” then “Close”.
Close the “Internet Options” dialog box with either “OK” or “Cancel”.
Refresh the current page.
When told “There is a problem with this website's security certificate.”, c...
What is sr-only in Bootstrap 3?
... @Christophe I would still recommend that article for understanding the concept. Even though it doesn't explain the problems with rtl content it does list different techniques which also includes clipping
– katranci
Jan 20 '14 at 12:02
...
Checkout old commit and make it a new commit [duplicate]
On Git, say I mess up my commits, and I want to make the version 3 commits ago as the new version. If I do git checkout xxxx , it creates a new branch and it seems like I can only merge it? Could I make this the new "master version"?
...
Basic http file downloading and saving to disk in python?
I'm new to Python and I've been going through the Q&A on this site, for an answer to my question. However, I'm a beginner and I find it difficult to understand some of the solutions. I need a very basic solution.
...
Why is [1,2] + [3,4] = “1,23,4” in JavaScript?
...d for arrays.
What happens is that Javascript converts arrays into strings and concatenates those.
Update
Since this question and consequently my answer is getting a lot of attention I felt it would be useful and relevant to have an overview about how the + operator behaves in general also.
So, h...