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Why should I declare a virtual destructor for an abstract class in C++?
I know it is a good practice to declare virtual destructors for base classes in C++, but is it always important to declare virtual destructors even for abstract classes that function as interfaces? Please provide some reasons and examples why.
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Making interface implementations async
...Async();
IIO asSync = asAsync;
Console.WriteLine(DateTime.Now.Second);
asAsync.DoOperation();
Console.WriteLine("After call to sync func using Async iface: {0}",
DateTime.Now.Second);
asAsync.DoOperationAsync().GetAwaiter().GetResult();
...
Safely turning a JSON string into an object
...
The jQuery method is now deprecated. Use this method instead:
let jsonObject = JSON.parse(jsonString);
Original answer using deprecated jQuery functionality:
If you're using jQuery just use:
jQuery.parseJSON( jsonString );
It's exactly w...
Disable firefox same origin policy
...om here
(mirror, may not be updated).
Or download the files from GitHub.
Now it's also on Firefox Marketplace: Download here. In this case, the addon is installed after you click install and you can skip to step 4.
If you downloaded the xpi you can jump to step 3. If you downloaded the zip from G...
Using async-await on .net 4
... http://blogs.msdn.com/b/bclteam/archive/2013/04/17/microsoft-bcl-async-is-now-stable.aspx.
You can read about the previous version here: http://blogs.msdn.com/b/lucian/archive/2012/04/24/async-targeting-pack.aspx.
As this pack is officially supported, I now believe the best option for targeting X...
Download single files from GitHub
... the URL format mentioned in the answer (raw after the repository name) is now automatically redirected to the format you mention (hostname raw.github.com). When in doubt, browse to the file in question on github.com and click on the 'Raw' button.
– mklement0
A...
Update multiple rows in same query using PostgreSQL
...ate table results_dummy (id int, status text, created_at timestamp default now(), updated_at timestamp default now());
-- populate table with dummy rows
insert into results_dummy
(id, status)
select unnest(array[1,2,3,4,5]::int[]) as id, unnest(array['a','b','c','d','e']::text[]) as status;
select ...
JavaScript: Check if mouse button down?
...ks more than one button intentionally or accidentally. Don't ask me how I know :-(.
The correct code should be like that:
var mouseDown = 0;
document.body.onmousedown = function() {
++mouseDown;
}
document.body.onmouseup = function() {
--mouseDown;
}
With the test like this:
if(mouseDown){...
Should 'using' directives be inside or outside the namespace?
...c void Bar()
{
double d = Math.PI;
}
}
}
Now imagine that someone adds another file (File2.cs) to the project that looks like this:
// File2.cs
namespace Outer
{
class Math
{
}
}
The compiler searches Outer before looking at those using directives out...
Docker build “Could not resolve 'archive.ubuntu.com'” apt-get fails to install anything
...un Docker build on various files which previously worked before, which are now no longer working.
14 Answers
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