大约有 40,000 项符合查询结果(耗时:0.0325秒) [XML]
Is it intended by the C++ standards committee that in C++11 unordered_map destroys what it inserts?
...lost three days of my life tracking down a very strange bug where unordered_map::insert() destroys the variable you insert. This highly non-obvious behaviour occurs in very recent compilers only: I found that clang 3.2-3.4 and GCC 4.8 are the only compilers to demonstrate this "feature".
...
How do I check if an object has a specific property in JavaScript?
...2: " + prop );
}
function hasOwnProperty(obj, prop) {
var proto = obj.__proto__ || obj.constructor.prototype;
return (prop in obj) &&
(!(prop in proto) || proto[prop] !== obj[prop]);
}
if ( Object.prototype.hasOwnProperty ) {
var hasOwnProperty = function(obj, prop) {
...
搭建高可用mongodb集群(二)—— 副本集 - 大数据 & AI - 清泛网 - 专注C/...
...安装程序包
wget http://fastdl.mongodb.org/linux/mongodb-linux-x86_64-2.4.8.tgz
注意linux生产环境不能安装32位的mongodb,因为32位受限于操作系统最大2G的文件限制。
#解压下载的压缩包
tar xvzf mongodb-linux-x86_64-2.4.8.tgz
4、分别在...
How to avoid having class data shared among instances?
...
You want this:
class a:
def __init__(self):
self.list = []
Declaring the variables inside the class declaration makes them "class" members and not instance members. Declaring them inside the __init__ method makes sure that a new instance of th...
How does _gaq.push(['_trackPageLoadTime']) work?
How does the Google Analytics Site Speed feature, _gaq.push(['_trackPageLoadTime']) , work? Is there any documentation about how it works?
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How do I convert between big-endian and little-endian values in C++?
...n.h and call the following functions:
For 16 bit numbers:
unsigned short _byteswap_ushort(unsigned short value);
For 32 bit numbers:
unsigned long _byteswap_ulong(unsigned long value);
For 64 bit numbers:
unsigned __int64 _byteswap_uint64(unsigned __int64 value);
8 bit numbers (chars) don'...
[完整源码实例] 修改 CListCtrl 的标题栏字体颜色;重绘 CListCtrl 标题栏 ...
... 0, // cStrikeOut
ANSI_CHARSET, // nCharSet
OUT_DEFAULT_PRECIS, // nOutPrecision
CLIP_DEFAULT_PRECIS, // nClipPrecision
DEFAULT_QUALI...
How to include external Python code to use in other files?
...
You may interesting imp module and magic call __import__.
– Vitold S.
Dec 5 '15 at 23:53
...
Importing from a relative path in Python
...port things):
import sys, os
sys.path.append(os.path.join(os.path.dirname(__file__), '..', 'Common'))
import Common
os.path.dirname(__file__) just gives you the directory that your current python file is in, and then we navigate to 'Common/' the directory and import 'Common' the module.
...
When saving, how can you check if a field has changed?
...
Essentially, you want to override the __init__ method of models.Model so that you keep a copy of the original value. This makes it so that you don't have to do another DB lookup (which is always a good thing).
class Person(models.Model):
name = models.CharF...
