大约有 40,000 项符合查询结果（耗时：0.0229秒） [XML]
Best explanation for languages without null
... that every reference type gets this extra state in its space that is typically undesired. A string variable could be any sequence of characters, or it could be this crazy extra null value that doesn't map into my problem domain. A Triangle object has three Points, which themselves have X and Y va...
What is “:-!!” in C code?
...sizeof(struct { int: -!!(e); }))
(e): Compute expression e.
!!(e): Logically negate twice: 0 if e == 0; otherwise 1.
-!!(e): Numerically negate the expression from step 2: 0 if it was 0; otherwise -1.
struct{int: -!!(0);} --> struct{int: 0;}: If it was zero, then we declare a struct with an an...
Ignore .pyc files in git repository
...t to to do it beforehand, if you just add the line to the .gitignore file, all previously committed .pyc files will still be tracked, so you'll need to remove them from the repository.
If you are on a Linux system (or "parents&sons" like a MacOSX), you can quickly do it with just this one line ...
Command-line Unix ASCII-based charting / plotting tool
...
While gnuplot is powerful, it's also really irritating when you just want to pipe in a bunch of points and get a graph.
Thankfully, someone created eplot (easy plot), which handles all the nonsense for you.
It doesn't seem to have an option to force terminal gra...
How to add an integer to each element in a list?
...ition, but if you have a more complex function that you needed to apply to all the elements then map may be a good fit.
In your example it would be:
>>> map(lambda x:x+1, [1,2,3])
[2,3,4]
share
|
...
How can I force division to be floating point? Division keeps rounding down to 0?
... a floating point number in Python in the following?
c = a / b
What is really being asked here is:
"How do I force true division such that a / b will return a fraction?"
Upgrade to Python 3
In Python 3, to get true division, you simply do a / b.
>>> 1/2
0.5
Floor division, the classic di...
Force SSL/https using .htaccess and mod_rewrite
...that expose stuff that should be protected. When this directive is present all requests are denied which are not using SSL.
This will not do a redirect to https though. To redirect, try the following with mod_rewrite in your .htaccess file
RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^ ...
Maven fails to find local artifact
Occasionally maven complains that a particular dependency, which is built and packaged locally, cannot be found in the local repository while building another project that has it as a dependency. We get an error like:
...
How do I show the value of a #define at compile-time?
...ring. When there is more than one component to the argument then they must all be strings so that string concatenation can be applied. The preprocessor can never assume that an unquoted string should be treated as if it were quoted. If it did then:
#define ABC 123
int n = ABC;
would not compile.
...
How can I create directory tree in C++/Linux?
...C++ compilers.
/*
@(#)File: mkpath.c
@(#)Purpose: Create all directories in path
@(#)Author: J Leffler
@(#)Copyright: (C) JLSS 1990-2020
@(#)Derivation: mkpath.c 1.16 2020/06/19 15:08:10
*/
/*TABSTOP=4*/
#include "posixver.h"
#include "mkpath.h"
#include "emalloc...