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Ruby replace string with captured regex pattern
... note that you can index a string with a regex:
"foo"[/oo/]
#=> "oo"
"Z_123: foobar"[/^Z_.*(?=:)/]
#=> "Z_123"
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What is “:-!!” in C code?
...ld.
The macro is somewhat misnamed; it should be something more like BUILD_BUG_OR_ZERO, rather than ...ON_ZERO. (There have been occasional discussions about whether this is a confusing name.)
You should read the expression like this:
sizeof(struct { int: -!!(e); }))
(e): Compute expression e....
“Private” (implementation) class in Python
...
Use a single underscore prefix:
class _Internal:
...
This is the official Python convention for 'internal' symbols; "from module import *" does not import underscore-prefixed objects.
Edit: Reference to the single underscore convention
...
Convert a row of a data frame to vector
...u have to be careful if your row contains a factor. Here is an example:
df_1 = data.frame(V1 = factor(11:15),
V2 = 21:25)
df_1[1,] %>% as.numeric() # you expect 11 21 but it returns
[1] 1 21
Here is another example (by default data.frame() converts characters to factors)
d...
How to initialize a private static const map in C++?
...ap>
using namespace std;
struct A{
static map<int,int> create_map()
{
map<int,int> m;
m[1] = 2;
m[3] = 4;
m[5] = 6;
return m;
}
static const map<int,int> myMap;
};
const map<int,int> A:: myMap = ...
How do I get indices of N maximum values in a NumPy array?
...t;> a = [1, 3, 2, 4, 5]
>>> heapq.nlargest(3, range(len(a)), a.__getitem__)
[4, 3, 1]
If you use Python 2, use xrange instead of range.
Source: heapq — Heap queue algorithm
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How can I use “sizeof” in a preprocessor macro?
....
Following snippets will produce no code if sizeof(someThing) equals PAGE_SIZE; otherwise they will produce a compile-time error.
1. C11 way
Starting with C11 you can use static_assert (requires #include <assert.h>).
Usage:
static_assert(sizeof(someThing) == PAGE_SIZE, "Data structure do...
What is the JavaScript equivalent of var_dump or print_r in PHP? [duplicate]
...e of object in JavaScript (for debugging). Is there anything similar to var_dump in PHP?
9 Answers
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How do I use PHP namespaces with autoload?
...in the global scope.
See below for a working example:
<?php
function __autoload($class)
{
$parts = explode('\\', $class);
require end($parts) . '.php';
}
use Person\Barnes\David as MyPerson;
$class = new MyPerson\Class1();
Edit (2009-12-14):
Just to clarify, my usage of "use ... a...
Understanding typedefs for function pointers in C
... can use it to declare variables and so on. For example:
static void alarm_catcher(int signum)
{
fprintf(stderr, "%s() called (%d)\n", __func__, signum);
}
static void signal_catcher(int signum)
{
fprintf(stderr, "%s() called (%d) - exiting\n", __func__, signum);
exit(1);
}
static str...