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How to call a parent class function from derived class function?
...disambiguate it by adding the base class's name followed by two colons base_class::foo(...). You should note that unlike Java and C#, C++ does not have a keyword for "the base class" (super or base) since C++ supports multiple inheritance which may lead to ambiguity.
class left {
public:
void f...
Using the HTML5 “required” attribute for a group of checkboxes?
...="checkbox-group required">
<input type="checkbox" name="checkbox_name[]">
<input type="checkbox" name="checkbox_name[]">
<input type="checkbox" name="checkbox_name[]">
<input type="checkbox" name="checkbox_name[]">
</div>
You can use this expressio...
awk without printing newline
...
awk '{sum+=$3}; END {printf "%f",sum/NR}' ${file}_${f}_v1.xls >> to-plot-p.xls
print will insert a newline by default. You dont want that to happen, hence use printf instead.
share
|...
How to export all collections in MongoDB?
...
For lazy people, use mongodump, it's faster:
mongodump -d <database_name> -o <directory_backup>
And to "restore/import" it (from directory_backup/dump/):
mongorestore -d <database_name> <directory_backup>
This way, you don't need to deal with all collections individ...
How to clear MemoryCache?
...ntHandler<SignaledChangeEventArgs> Signaled;
private string _name;
private string _uniqueId = Guid.NewGuid().ToString("N", CultureInfo.InvariantCulture);
public override string UniqueId
{
get { return _uniqueId; }
}
public Signaled...
Why is GHC so large/big?
...njdk/jdk7) vs GHC 7 source bundle, which is 23 MB (haskell.org/ghc/download_ghc_7_0_1). GHC is not big here. Runtime size: openjdk-6-jre-headless on Ubuntu is 77 MB uncompressed vs Haskell helloworld, statically linked with its runtime, which is <1 MB. GHC is not big here.
Where GHC is big, is t...
Curly braces in string in PHP
...eral {$. Some examples to make it clear:
<?php
// Show all errors
error_reporting(E_ALL);
$great = 'fantastic';
// Won't work, outputs: This is { fantastic}
echo "This is { $great}";
// Works, outputs: This is fantastic
echo "This is {$great}";
echo "This is ${great}";
// Works
echo "This sq...
Is using a lot of static methods a bad thing?
...:
public static class ResourceLoader
{
public static void Init(string _rootPath) { ... etc. }
public static void GetResource(string _resourceName) { ... etc. }
public static void Quit() { ... etc. }
}
public static class TextureManager
{
private static Dictionary<string, Textur...
TransactionManagementError “You can't execute queries until the end of the 'atomic' block” while usi
...ementError when trying to save a Django User model instance and in its post_save signal, I'm saving some models that have the user as the foreign key.
...
“Failed to load platform plugin ”xcb“ ” while launching qt5 app on linux without qt installed
... place as your binary or shared library file. If that works, you may set LD_LIBRARY_PATH (hacky) or, as mentioned in the answer by @bossbarber, QT_QPA_PLATFORM_PLUGIN_PATH.
– csl
Oct 6 '16 at 7:06
...