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What is the purpose of the word 'self'?
...attributes -- special syntax like Ruby has, or requiring declarations like C++ and Java do, or perhaps something yet more different -- but it didn't. Python's all for making things explicit, making it obvious what's what, and although it doesn't do it entirely everywhere, it does do it for instance...
What's the fundamental difference between MFC and ATL?
...answer:
MFC was built in the early 90s to try out this new language called C++ and apply it to Windows. It made Office like features available to the development community when the OS didn't have them yet.
[Edit embellishment: I did not work at Microsoft, so I don't know if Office was ever built ...
Why doesn't C have unsigned floats?
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Why C++ doesn't have support for unsigned floats is because there is no equivalent machine code operations for the CPU to execute. So it would be very inefficient to support it.
If C++ did support it, then you would be someti...
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...
Heap vs Binary Search Tree (BST)
...ed Priority Queue? e.g. for Dijkstra. Possible at no extra time cost.
GCC C++ standard library insert benchmark on real hardware
I benchmarked the C++ std::set (Red-black tree BST) and std::priority_queue (dynamic array heap) insert to see if I was right about the insert times, and this is what I ...
Will using goto leak variables?
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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'...
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:
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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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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...