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How to tell if UIViewController's view is visible
...here a way to know if a particular UIViewController is currently visible from within the UIViewController ? (looking for a property)
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What differences, if any, between C++03 and C++11 can be detected at run-time?
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I got an inspiration from What breaking changes are introduced in C++11?:
#define u8 "abc"
bool isCpp0x() {
const std::string s = u8"def"; // Previously "abcdef", now "def"
return s == "def";
}
This is based on the new string literals t...
Unsigned keyword in C++
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From the link above:
Several of these types can be modified using the keywords signed, unsigned, short, and long. When one of these type modifiers is used by itself, a data type of int is assumed
This means that you can...
How do I get out of a screen without typing 'exit'?
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Ctrl-A -> Ctrl-D just exits from the session for me, leaving it running in the background. Ctrl-A -> \ will exit the session completely (on Oracle Linux 6).
– Andrew Brennan
Apr 1 '19 at 16:03
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What is “incremental linking”?
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Linking involves packaging together all of the .obj files built from your source files, as well as any .lib files you reference, into your output (eg .exe or .dll).
Without incremental linking, this has to be done from scratch each time.
Incremental linking links your exe/dll in a way w...
What are all the valid self-closing elements in XHTML (as implemented by the major browsers)?
...ut browsers follow it religiously. Read
Understanding HTML, XML and XHTML from WebKit blog:
In fact, the vast majority of supposedly XHTML documents on the internet are served as text/html. Which means they are not XHTML at all, but actually invalid HTML that’s getting by on the error handlin...
OSError: [Errno 2] No such file or directory while using python subprocess in Django
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Use shell=True if you're passing a string to subprocess.call.
From docs:
If passing a single string, either shell must be True or
else the string must simply name the program to be executed without
specifying any arguments.
subprocess.call(crop, shell=True)
or:
import shlex...
When NOT to use yield (return) [duplicate]
...t get thrown until the iterator is
// iterated, which can be very far away from this method invocation
public IEnumerable<string> Foo(Bar baz)
{
if (baz == null)
throw new ArgumentNullException();
yield ...
}
// DO this
public IEnumerable<string> Foo(Bar baz)
{
if ...
Choosing between qplot() and ggplot() in ggplot2 [closed]
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One more variant from me: I use qplot when I'm typing directly into the console, and ggplot when I'm writing scripts. But after finding over and over again that I want to recreate a plot I typed into the console 15 minutes earlier, I write a...
using awk with column value conditions
I'm learning awk from The AWK Programming Language and I have a problem with one of the examples.
6 Answers
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