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Do I need to manually close an ifstream?
...tor do its job. There is no harm in closing it manually, but it's not the C++ way, it's programming in C with classes.
If you want to close the file before the end of a function you can always use a nested scope.
In the standard (27.8.1.5 Class template basic_ifstream), ifstream is to be implemente...
How to set up Spark on Windows?
...ch as if you do not have a recent version of MS-VS. (You will need a Win32 C++ compiler, but you can install MS VS Community Edition free.)
I've tried this with Spark 1.2.2 and mahout 0.10.2 as well as with the latest versions in November 2015. There are a number of problems including the fact tha...
Why is processing a sorted array faster than processing an unsorted array?
Here is a piece of C++ code that shows some very peculiar behavior. For some strange reason, sorting the data miraculously makes the code almost six times faster:
...
Will using goto leak variables?
...
Warning: This answer pertains to C++ only; the rules are quite different in C.
Won't x be leaked?
No, absolutely not.
It is a myth that goto is some low-level construct that allows you to override C++'s built-in scoping mechanisms. (If anything, it'...
How are virtual functions and vtable implemented?
We all know what virtual functions are in C++, but how are they implemented at a deep level?
12 Answers
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各编程语言读写文件汇总 - C/C++ - 清泛网 - 专注C/C++及内核技术
...ets、fputs文本读写
3.2、fread、fwrite二进制读写
四、C++
五、Java
PHP读写文件:
// 写文件
$fp = fopen("log.txt", "a");
fwrite($fp, $str);
fclose($fp);
// 读文件
$fp = fopen("log.txt", "r");
while(!feof($fp)) {
$line = fgets($fp);
echo $line;
}
...
Do the parentheses after the type name make a difference with new?
...ns POD members and is using a compiler-generated default constructor.
In C++1998 there are 2 types of initialization: zero and default
In C++2003 a 3rd type of initialization, value initialization was added.
Assume:
struct A { int m; }; // POD
struct B { ~B(); int m; }; // non-POD, compiler gen...
Is it safe to use -1 to set all bits to true?
I've seen this pattern used a lot in C & C++.
20 Answers
20
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How does libuv compare to Boost/ASIO?
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Scope
Boost.Asio is a C++ library that started with a focus on networking, but its asynchronous I/O capabilities have been extended to other resources. Additionally, with Boost.Asio being part of the Boost libraries, its scope is slightly narrowe...
CFLAGS vs CPPFLAGS
I understand that CFLAGS (or CXXFLAGS for C++) are for the compiler, whereas CPPFLAGS is used by the preprocessor.
4 Answer...