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How to generate a random number in C++?
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The most fundamental problem of your test application is that you call srand once and then call rand one time and exit.
The whole point of srand function is to initialize the sequence of pseudo-random numbers with a random seed.
It means that if you pass the same value to srand in two differ...
MySQL select where column is not empty
...nd another plus over the COALESCE() and IFNULL() functions is that this is index friendly, since you're not comparing the output of a function on a field to anything.
Test cases:
SELECT if(NULL > '','true','false');-- false
SELECT if('' > '','true','false');-- false
SELECT if(' ' > '','tr...
ASP.NET Web API - PUT & DELETE Verbs Not Allowed - IIS 8
...tly upgraded from Visual Studio 2010 to the Visual Studio 2012 RC. The installer also installs IIS 8 Express which Visual Studio now uses as the default web server.
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Cross-browser multi-line text overflow with ellipsis appended within a fixed width and height
...fos').height();
while ($p.outerHeight() > divh) {
$p.text(function (index, text) {
return text.replace(/\W*\s(\S)*$/, '...');
});
}
It repeatedly tries to remove the last word of the text until it reaches the desired size. Because of the overflow: hidden; the process remains inv...
理解Python的 with 语句 - 大数据 & AI - 清泛网 - 专注C/C++及内核技术
...hat the statement after with has to evaluate an object that responds to an __enter__() as well as an __exit__() function.
这看起来充满魔法，但不仅仅是魔法，Python对with的处理还很聪明。基本思想是with所求值的对象必须有一个__enter__()方法，一个__exit__()...
Default template arguments for function templates
Why are default template arguments only allowed on class templates? Why can't we define a default type in a member function template? For example:
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Node.js app can't run on port 80 even though there's no other process blocking the port
I'm running an instance of Debian on Amazon EC2 with Node.js installed. If I run the code below:
9 Answers
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node.js fs.readdir recursive directory search
... search using fs.readdir? I realise that we could introduce recursion and call the read directory function with the next directory to read, but am a little worried about it not being async...
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How to print out the method name and line number and conditionally disable NSLog?
...lot:
#ifdef DEBUG
# define DLog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE__, ##__VA_ARGS__)
#else
# define DLog(...)
#endif
// ALog always displays output regardless of the DEBUG setting
#define ALog(fmt, ...) NSLog((@"%s [Line %d] " fmt), __PRETTY_FUNCTION__, __LINE_...
Forward declaring an enum in C++
...can't know the storage required for the enum variable. C++ Compiler's are allowed to specify the actual storage space based on the size necessary to contain all the values specified. If all that is visible is the forward declaration, the translation unit can't know what storage size will have been...