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(How) can I count the items in an enum?
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There's not really a good way to do this, usually you see an extra item in the enum, i.e.
enum foobar {foo, bar, baz, quz, FOOBAR_NR_ITEMS};
So then you can do:
int fuz[FOOBAR_NR_ITEMS];
Still not very nice though.
But of course you...
Get ffmpeg information in friendly way
...eed to tell ffprobe what information you want it to display (with the -show_format, -show_packets and -show_streams options) or it'll just give you blank output (like you mention in one of your comments).
For example, ffprobe -v quiet -print_format json -show_format -show_streams somefile.asf would...
Draw in Canvas by finger, Android
...ur onDraw() you draw the paths using the paint of your choice. You should call invalidate() to refresh the view.
To choose options you can click menu and choose the options.
The below can be used as a reference. You can modify the below according to your needs.
public class FingerPaintActivity ex...
What exactly is a reentrant function?
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1. How is safely defined?
Semantically. In this case, this is not a hard-defined term. It just mean "You can do that, without risk".
2. If a program can be safely executed concurrently, does it always mean that it is reentrant?
No.
For example, let's have ...
ArrayBuffer to base64 encoded string
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I like the simplicity of this approach, but all that string concatenation can be costly. It looks like building an array of the characters and join()ing them at the end is significantly faster on Firefox, IE, and Safari (but quite a lot slower on Chrome): jsperf.com/to...
Detect if stdin is a terminal or pipe?
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Summary
For many use cases the POSIX function isatty() is all what it is needed to detect if stdin is connected to a terminal. A minimal example:
#include <unistd.h>
#include <stdio.h>
int main(int argc, char **argv)
{
if (isatty(fileno(stdin)))
puts("stdin is co...
Change Oracle port from port 8080
... Production on Tue Aug 26 10:40:44 2008
Copyright (c) 1982, 2005, Oracle. All rights reserved.
SQL> connect
Enter user-name: system
Enter password: <enter password if will not be visible>
Connected.
SQL> Exec DBMS_XDB.SETHTTPPORT(3010); [Assuming you want to have HTTP going to this po...
What happens if i return before the end of using statement? Will the dispose be called?
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Yes, Dispose will be called. It's called as soon as the execution leaves the scope of the using block, regardless of what means it took to leave the block, be it the end of execution of the block, a return statement, or an exception.
As @Noldor...
Why would I ever use push_back instead of emplace_back?
...ob is to generate the code you wrote. The optimizing compiler's job is actually to generate the code you would have written if you were an expert on platform-specific optimizations and did not care about maintainability, just performance.
The actual difference between these two statements is that t...
When is std::weak_ptr useful?
...want to keep them in memory, so you hold a strong pointer to them. Periodically, you scan the cache and decide which objects have not been accessed recently. You don't need to keep those in memory, so you get rid of the strong pointer.
But what if that object is in use and some other code holds a s...