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c++ Programming Glossary: noticeWhy is my program slow when looping over exactly 8192 elements? http://stackoverflow.com/questions/12264970/why-is-my-program-slow-when-looping-over-exactly-8192-elements k 2 k for l 1 l 2 l res j i img j l i k res j i 9 First notice that the two inner loops are trivial. They can be unrolled as..
http://stackoverflow.com/questions/131803/unsigned-int-vs-size-t int vs. size_t I notice that modern C and C code seems to use size_t instead of int..
Why aren't my include guards preventing recursive inclusion and multiple symbol definitions? http://stackoverflow.com/questions/14909997/why-arent-my-include-guards-preventing-recursive-inclusion-and-multiple-symbol this to compile... #include a.h int main ... You'll notice that the compiler will report a failure when it reaches the.. file that is #include d by multiple translation units notice that no problem will arise if your header is #include d just..
Setting the internal buffer used by a standard stream (pubsetbuf) http://stackoverflow.com/questions/1494182/setting-the-internal-buffer-used-by-a-standard-stream-pubsetbuf bufferLength Now if you look at my original code you will notice that I didn't really need a stringstream to begin with. All..
How to pass parameters correctly? http://stackoverflow.com/questions/15600499/how-to-pass-parameters-correctly obj bar std forward C obj std forward C obj Dangerous Also notice that you normally do not resort to the template based solution..
http://stackoverflow.com/questions/162941/why-use-pointers memory but you do not know what is in there. Also do notice that the two printf might give you different addresses since..
Static linking vs dynamic linking http://stackoverflow.com/questions/1993390/static-linking-vs-dynamic-linking static linking. Unless modern OS's are smart enough to notice identical segments in statically linked binaries. Seems hard..
Why do people use __(double underscore) so much in C++ http://stackoverflow.com/questions/224397/why-do-people-use-double-underscore-so-much-in-c C I was having a look through some open source C code and notice a lot of double under scores where used in the code mainly at..
CRTP to avoid dynamic polymorphism http://stackoverflow.com/questions/262254/crtp-to-avoid-dynamic-polymorphism will do static dispatch struct not_derived_from_base notice not derived from base ... my_type my_instance your_type your_instance..
http://stackoverflow.com/questions/3106110/what-is-move-semantics would be very surprised if x had changed somehow. Did you notice how I just said x three times four times if you include this..
What is the copy-and-swap idiom? http://stackoverflow.com/questions/3279543/what-is-the-copy-and-swap-idiom are elegantly tackled at once. Why does it work We first notice an important choice the parameter argument is taken by value..
When to use virtual destructors? http://stackoverflow.com/questions/461203/when-to-use-virtual-destructors Base ~Derived Do some important cleanup Here you'll notice that I didn't declare Base's destructor to be virtual. Now let's..
http://stackoverflow.com/questions/4707012/c-memcpy-vs-stdcopy loss. I just did a test and found that to be untrue I did notice a performance difference. However the winner was std copy. I..
Flags to enable thorough and verbose g++ warnings http://stackoverflow.com/questions/5088460/flags-to-enable-thorough-and-verbose-g-warnings to slip by. Turning warnings into errors ensures that I notice them. Then there is a set of warnings that are not included.. as part of another warning I do mention. If anyone notices any warnings that are excluded from this post entirely let..
What's this STL vs. “C++ Standard Library” fight all about? [closed] http://stackoverflow.com/questions/5205491/whats-this-stl-vs-c-standard-library-fight-all-about the first time do not know this distinction and may not notice small language differences. The author of that article has numerous..
smart pointers (boost) explained http://stackoverflow.com/questions/569775/smart-pointers-boost-explained the weak_ptr points to an object already deleted it will notice you by throwing an exception. Using weak_ptr is most beneficial..
how to achieve 4 FLOPs per cycle http://stackoverflow.com/questions/8389648/how-to-achieve-4-flops-per-cycle the 48 instructions inside the inner loop. You'll notice that it's broken into 4 blocks of 12 instructions each. Each..
Why is one loop so much slower than two loops? http://stackoverflow.com/questions/8547778/why-is-one-loop-so-much-slower-than-two-loops two tests the arrays are allocated separately. You'll notice that they all have the same alignment relative to the page... are packed together to break that alignment. Here you'll notice both loops are faster. Furthermore the second double loop is..
OpenCv 2.3 C - How to isolate object inside image http://stackoverflow.com/questions/10315551/opencv-2-3-c-how-to-isolate-object-inside-image the box to achieve the crop effect and isolate the object Notice that in the resulting image there is one extra row column of..
Is there a difference in C++ between copy initialization and direct initialization? http://stackoverflow.com/questions/1051379/is-there-a-difference-in-c-between-copy-initialization-and-direct-initializati will find the following candidates B A const operator B A Notice how I rewrote the conversion function The parameter type reflects..
Calling Objective-C method from C++ method? http://stackoverflow.com/questions/1061005/calling-objective-c-method-from-c-method void logMyMessage char aCStr private void self #endif Notice the wrapper methods no longer require the void pointer to an.. result void logMyMessage char aCStr NSLog aCStr @end Notice that MyClass is instantiated with a call to MyClassImpl init...
Why is processing a sorted array faster than an unsorted array? http://stackoverflow.com/questions/11227809/why-is-processing-a-sorted-array-faster-than-an-unsorted-array the culprit is this if statement if data c 128 sum data c Notice that the data is evenly distributed between 0 and 255. When..
How can avoid the Diamond of Death in C++ if I use multiple inheritance? http://stackoverflow.com/questions/137282/how-can-avoid-the-diamond-of-death-in-c-if-i-use-multiple-inheritance B public A class C public A class D public B public C Notice how class D inherits from both B C. But both B C inherit from..
How to pass parameters correctly? http://stackoverflow.com/questions/15600499/how-to-pass-parameters-correctly reference binding my_class copyOfObj std move obj Move Notice that invoking std move is necessary here because obj is an..
Is it okay to inherit implementation from STL containers, rather than delegate? http://stackoverflow.com/questions/2034916/is-it-okay-to-inherit-implementation-from-stl-containers-rather-than-delegate 5 Example iterator i nested types are especially easier Notice the value_type and allocator can change without affecting later..
How to make SIMPLE C++ Makefile? http://stackoverflow.com/questions/2481269/how-to-make-simple-c-makefile support.cc which is easier to type and much more readable. Notice that We are still stating explicitly the dependencies for each.. RM OBJS dist clean clean RM ~ .dependtool include .depend Notice that There are no longer any dependency lines for the source..
Is the return type part of the function signature? http://stackoverflow.com/questions/290038/is-the-return-type-part-of-the-function-signature the return type is not part of the signature. Notice however that the return type in any case is a significant part..
http://stackoverflow.com/questions/2910979/how-is-base-of-works the case here Both use the second conversion function. Notice that thus the const is important because it forces the compiler.. function is selected and we recognize the inheritance Notice that since we never needed to actually convert to a base class..
How to use std::sort with a vector of structures and compare function? http://stackoverflow.com/questions/328955/how-to-use-stdsort-with-a-vector-of-structures-and-compare-function rewrite your above function to accomplish the same thing. Notice that you have to use strong typing in the arguments. Additionally..
Convert std::string to const char* or char* http://stackoverflow.com/questions/347949/convert-stdstring-to-const-char-or-char the string after finished using it delete writable Edit Notice that the above is not exception safe. If anything between the..
http://stackoverflow.com/questions/402283/stdwstring-vs-stdstring all the ASCII character set including special characters Notice A std string is suitable for holding a 'binary' buffer where..
What does T&& (double ampersand) mean in C++11? http://stackoverflow.com/questions/5481539/what-does-t-double-ampersand-mean-in-c11 this ptr other.ptr other.length 0 other.ptr nullptr Notice the big difference here the move constructor actually modifies..
Dual emission of constructor symbols http://stackoverflow.com/questions/6921295/dual-emission-of-constructor-symbols You can read the constructor names similarly as below. Notice how the constructor name isn't given but instead a C clause..
How can I get a process handle by its name in C++? http://stackoverflow.com/questions/865152/how-can-i-get-a-process-handle-by-its-name-in-c so I can call TerminateProcess on it. How can I do this Notice it doesn't have a window so FindWindow won't work. c winapi..
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