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Performance of FOR vs FOREACH in PHP
... iterators, foreach is equivalent to:
$it->rewind();
while ($it->valid()) {
$key = $it->key(); // If using the $key => $value syntax
$value = $it->current();
// Contents of loop in here
$it->next();
}
As far as there being faster ways to iterate, it really ...
val-mutable versus var-immutable in Scala
Are there any guidelines in Scala on when to use val with a mutable collection versus using var with an immutable collection? Or should you really aim for val with an immutable collection?
...
How does RegexOptions.Compiled work?
...e faster.
If you do not specify this flag, your regular expression is considered "interpreted".
Take this example:
public static void TimeAction(string description, int times, Action func)
{
// warmup
func();
var watch = new Stopwatch();
watch.Start();
for (int i = 0; i < ...
How can I make setuptools install a package that's not on PyPI?
...tarball/master#egg=gearman-2.0.0beta instead, easy_install will be able to identify the package name and its version.
The final step is to add the URL to your package's dependency_links, e.g.:
setup(
...
dependency_links = ['http://github.com/mtai/python-gearman/tarball/master#egg=gearman-2....
When do I use a dot, arrow, or double colon to refer to members of a class in C++?
...small print:
In C++, types declared as class, struct, or union are considered "of class type". So the above refers to all three of them.
References are, semantically, aliases to objects, so I should have added "or reference to a pointer" to the #3 as well. However, I thought this would be more...
stringstream, string, and char* conversion confusion
... any changes to it might cause it to re-allocate and thus render cstr invalid. It is therefor safer to not to store the result of the call to str() at all and use cstr only until the end of the full expression:
use_c_str( stringstream.str().c_str() );
Of course, the latter might not be easy and c...
Exporting functions from a DLL with dllexport
... the internals of your lib but export some functions unmangled for use outside C++, see the second section below.
Exporting/Importing DLL Libs in VC++
What you really want to do is define a conditional macro in a header that will be included in all of the source files in your DLL project:
#ifdef LIB...
Generating an MD5 checksum of a file
...y warnings, that is perfectly good use of MD5.
– President James K. Polk
Aug 7 '10 at 20:09
22
@G...
what exactly is device pixel ratio?
...any different device pixel ratios, you should use CSS Media Queries to provide different sets of resources for different groups of devices. Combine this with nice tricks like background-size: cover or explicitly set the background-size to percentage values.
Example
#element { background-image: url...
Pass a data.frame column name to a function
...,"x","y")
x y z
1 1 5 6
2 2 6 8
3 3 7 10
4 4 8 12
This is often considered "best practice" since it is the method that is hardest to screw up. Passing the column names as strings is about as unambiguous as you can get.
The following two options are more advanced. Many popular packages make u...