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How much is the overhead of smart pointers compared to normal pointers in C++?
...
std::unique_ptr has memory overhead only if you provide it with some non-trivial deleter.
std::shared_ptr always has memory overhead for reference counter, though it is very small.
std::unique_ptr has time overhead only during constru...
Environment variable to control java.io.tmpdir?
... there's a way to do this other than on Windows.
On Windows, OpenJDK's get_temp_directory() function makes a Win32 API call to GetTempPath(); this is how on Windows, Java reflects the value of the TMP environment variable.
On Linux and Solaris, the same get_temp_directory() functions return a stat...
How to find the Windows version from the PowerShell command line
...t is client or server Windows, nor the name of the version.
Use WMI's Win32_OperatingSystem class (always single instance), for example:
(Get-WmiObject -class Win32_OperatingSystem).Caption
will return something like
Microsoft® Windows Server® 2008 Standard
...
Python Progress Bar
... but maybe something very simple would do:
import time
import sys
toolbar_width = 40
# setup toolbar
sys.stdout.write("[%s]" % (" " * toolbar_width))
sys.stdout.flush()
sys.stdout.write("\b" * (toolbar_width+1)) # return to start of line, after '['
for i in xrange(toolbar_width):
time.sleep(...
Is there any pythonic way to combine two dicts (adding values for keys that appear in both)?
...+ b[k]) for k in set(b) & set(a)])
or even more generic:
def combine_dicts(a, b, op=operator.add):
return dict(a.items() + b.items() +
[(k, op(a[k], b[k])) for k in set(b) & set(a)])
For example:
>>> a = {'a': 2, 'b':3, 'c':4}
>>> b = {'a': 5, 'c':6, 'x':7...
How do I test a file upload in rails?
...ing to make it available on SO.
The rails framework has a function fixture_file_upload (Rails 2 Rails 3, Rails 5), which will search your fixtures directory for the file specified and will make it available as a test file for the controller in functional testing. To use it:
1) Put your file to be ...
@RequestParam vs @PathVariable
...re interesting annotation:
@MatrixVariable
http://localhost:8080/spring_3_2/matrixvars/stocks;BT.A=276.70,+10.40,+3.91;AZN=236.00,+103.00,+3.29;SBRY=375.50,+7.60,+2.07
And the Controller method for it
@RequestMapping(value = "/{stocks}", method = RequestMethod.GET)
public String showPortfo...
Loading Backbone and Underscore using RequireJS
...pendencies.
require.config({
shim: {
underscore: {
exports: '_'
},
backbone: {
deps: ["underscore", "jquery"],
exports: "Backbone"
}
}
});
//the "main" function to bootstrap your code
require(['jquery', 'underscore', 'backbone'], function ($, _, Backbone) { ...
How do I recursively delete a directory and its entire contents (files + sub dirs) in PHP?
...mdir contains a decent implementation:
function rrmdir($dir) {
if (is_dir($dir)) {
$objects = scandir($dir);
foreach ($objects as $object) {
if ($object != "." && $object != "..") {
if (is_dir($dir. DIRECTORY_SEPARATOR .$object) && !is_link($dir."/"...
Capture Image from Camera and Display in Activity
...ass MyCameraActivity extends Activity
{
private static final int CAMERA_REQUEST = 1888;
private ImageView imageView;
private static final int MY_CAMERA_PERMISSION_CODE = 100;
@Override
public void onCreate(Bundle savedInstanceState)
{
super.onCreate(savedInstanceSta...