大约有 46,000 项符合查询结果（耗时：0.0465秒） [XML]
Extracting bits with a single multiplication
.....
A multiplication is a bunch of shift-and-add operations. The key is to allow overflow to "shift away" the bits we don't need and put the ones we want in the right place.
Multiplication by 4 (00000100) would shift everything left by 2 and get you to a00b0000 . To get the b to move up we need to...
What is the difference between char s[] and char *s?
...puts the literal string in read-only memory and copies the string to newly allocated memory on the stack. Thus making
s[0] = 'J';
legal.
share
|
improve this answer
|
foll...
Cannot resolve the collation conflict between “SQL_Latin1_General_CP1_CI_AS” and “Latin1_General_CI_
...lations are needed and used when ordering and comparing strings. It's generally a good idea to have a single, unique collation used throughout your database - don't use different collations within a single table or database - you're only asking for trouble....
Once you've settled for one single col...
What techniques can be used to speed up C++ compilation times?
...ity that takes advantage of caching techniques to speed things up.
Use Parallelism
Many compilers / IDEs support using multiple cores/CPUs to do compilation simultaneously. In GNU Make (usually used with GCC), use the -j [N] option. In Visual Studio, there's an option under preferences to allow it...
What's the use of ob_start() in php?
...Think of ob_start() as saying "Start remembering everything that would normally be outputted, but don't quite do anything with it yet."
For example:
ob_start();
echo("Hello there!"); //would normally get printed to the screen/output to browser
$output = ob_get_contents();
ob_end_clean();
There a...
Symfony 2 EntityManager injection in service
...to inject doctrine EntityManager, but I don't see that __construct() is called on my service, and injection doesn't work.
...
Convert a row of a data frame to vector
...
Might have been changed in the meantime, but today unlist allows dropping names: identical(unlist(df[1,], use.names = FALSE), as.numeric(df[1,])) (and btw df still is not a sensible name for a data.frame... ;-))
– Andri Signorell
Sep 25 '1...
Open a URL in a new tab (and not a new window)
...e Javascript has nothing to do with how the new tab/window is opened. It's all determined by your browser's settings. Using window.open tells the browser to open something new, then the browser opens up what is chosen in its settings - tab or window. In the browsers you tested with, change the setti...
In Python, how do I read the exif data for an image?
...e. Some images are generated without EXIF data. If it is empty programmatically, try opening the image file in a photo editing software to check if it actually has EXIF data.
– Gino Mempin
Sep 6 at 0:03
...
Escaping regex string
...this:
4.2.3 re Module Contents
escape(string)
Return string with all non-alphanumerics backslashed; this is useful if you want to match an arbitrary literal string that may have regular expression metacharacters in it.
A simplistic example, search any occurence of the provided string opt...