大约有 4,600 项符合查询结果（耗时：0.0300秒） [XML]
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 ...
Does constexpr imply inline?
...
Yes ([dcl.constexpr], §7.1.5/2 in the C++11 standard): "constexpr functions and constexpr constructors are implicitly inline (7.1.2)."
Note, however, that the inline specifier really has very little (if any) effect upon whether a compiler is likely to expand a ...
error: ‘NULL’ was not declared in this scope
I get this message when compiling C++ on gcc 4.3
6 Answers
6
...
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...
Why doesn't C have unsigned floats?
...
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...
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 ...
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'...