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Inheriting constructors
...est()
{
D1 d(6); // Oops: d.x is not initialized
D1 e; // error: D1 has no default constructor
}
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How to get number of entries in a Lua table?
...ole table with pairs(..).
function tablelength(T)
local count = 0
for _ in pairs(T) do count = count + 1 end
return count
end
Also, notice that the "#" operator's definition is a bit more complicated than that. Let me illustrate that by taking this table:
t = {1,2,3}
t[5] = 1
t[9] = 1
Ac...
Is gcc 4.8 or earlier buggy about regular expressions?
....
Seriously though, who though that shipping an implementation of regex_search that only does "return false" was a good idea?
It wasn't such a bad idea a few years ago, when C++0x was still a work in progress and we shipped lots of partial implementations. No-one thought it would remain unusab...
Why is early return slower than else?
...e a theory for you.
I tried your code and get the same of results, without_else() is repeatedly slightly slower than with_else():
>>> T(lambda : without_else()).repeat()
[0.42015745017874906, 0.3188967452567226, 0.31984281521812363]
>>> T(lambda : with_else()).repeat()
[0.3600984...
How do I implement interfaces in python?
...the trick.
from abc import ABCMeta, abstractmethod
class IInterface:
__metaclass__ = ABCMeta
@classmethod
def version(self): return "1.0"
@abstractmethod
def show(self): raise NotImplementedError
class MyServer(IInterface):
def show(self):
print 'Hello, World 2!'
...
How to convert a DOM node list to an array in Javascript?
...
At least at latest chrome, 44, I get this: Uncaught TypeError: document.querySelectorAll is not a function(…)
– Nick
Mar 14 '16 at 7:14
...
top -c command in linux to filter processes listed based on processname
... to get pid's of matching command lines:
top -c -p $(pgrep -d',' -f string_to_match_in_cmd_line)
top -p expects a comma separated list of pids so we use -d',' in pgrep. The -f flag in pgrep makes it match the command line instead of program name.
...
Bash continuation lines
...here document. (Line terminators will still remain, though.)
cat <<-____HERE
continuation
lines
____HERE
See also http://ss64.com/bash/syntax-here.html
If you need to preserve some, but not all, leading whitespace, you might use something like
sed 's/^ //' <<____HERE
Th...
What's is the difference between include and extend in use case diagram?
...when certain criteria are met.
a typical example: between login and show error message (only happened sometimes)
(login) <--- << extend >> --- (show error message)
"show error message" only happens sometimes when the login process failed.
...
Placeholder in UITextView
...uble.
UIPlaceHolderTextView.h:
#import <Foundation/Foundation.h>
IB_DESIGNABLE
@interface UIPlaceHolderTextView : UITextView
@property (nonatomic, retain) IBInspectable NSString *placeholder;
@property (nonatomic, retain) IBInspectable UIColor *placeholderColor;
-(void)textChanged:(NSNotif...