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c++ Programming Glossary: butWhat is an undefined reference/unresolved external symbol error and how do I fix it? http://stackoverflow.com/questions/12573816/what-is-an-undefined-reference-unresolved-external-symbol-error-and-how-do-i-fix it simply assumes that that symbol was defined somewhere but it doesn't yet care where. The linking phase is responsible..
What can I use to profile C++ code in Linux? http://stackoverflow.com/questions/375913/what-can-i-use-to-profile-c-code-in-linux They will say that profilers give you this information but that is only true if they sample the entire call stack. Call.. opportunity to get speedup . Added It might not be obvious but the stack sampling technique works equally well in the presence.. and your first reaction is disbelief. That is natural but you can be sure if it finds a problem it is real and vice versa...
http://stackoverflow.com/questions/4172722/what-is-the-rule-of-three by default copying an object means copying its members but copying the name member merely copies a pointer not the character.. robust solution to this problem is the copy and swap idiom but I will not go into the details of exception safety here. I only..
Why can templates only be implemented in the header file? http://stackoverflow.com/questions/495021/why-can-templates-only-be-implemented-in-the-header-file way implementation is still separated from declaration but is accessible to the compiler. Another solution is to keep the..
Where and why do I have to put the “template” and “typename” keywords? http://stackoverflow.com/questions/610245/where-and-why-do-i-have-to-put-the-template-and-typename-keywords for parsing you don't need to know the meaning of a name but can just grammatically analyze the input and then create a parse.. up in. A value dependent expression 1 N is not a name but N is. The subset of all dependent constructs that are names.. meaning in different instantiations of a template but unfortunately are not caught by this general rule. Dependent..
Can a local variable's memory be accessed outside its scope? http://stackoverflow.com/questions/6441218/can-a-local-variables-memory-be-accessed-outside-its-scope table and go to sleep. You check out the next morning but forget to give back your key. You steal the key A week later.. sure why I considered it to be just a fun little analogy but whatever. I thought it might be germane to update this a bit.. lots of different ways of generating code to manage memory but over time two basic techniques have become entrenched. The first..
http://stackoverflow.com/questions/1120140/csv-parser-in-c then... then its only about three lines of code OK 14 But its only 15 to read the whole file . std vector std string getNextLineAndSplitIntoTokens.. CSVRow row while file row std cout 4th Element row 3 n But with a little work we could technically create an iterator class..
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 train could just signal the direction with a flag. But in computers the processor doesn't know which direction a branch.. branch predictors will typically achieve 90 hit rates. But when faced with unpredictable branches with no recognizable.. is not strictly equivalent to the original if statement. But in this case it's valid for all the input values of data . Benchmarks..
Why is “using namespace std;” considered bad practice? http://stackoverflow.com/questions/1452721/why-is-using-namespace-std-considered-bad-practice this question This is not related to performance at all. But consider this You are using two libraries called Foo and Bar.. can call Blah from Foo and Quux from Bar without problems. But one day you upgrade to a new version of Foo 2.0 which now offers..
Most effective way for float and double comparison http://stackoverflow.com/questions/17333/most-effective-way-for-float-and-double-comparison correct bool CompareDoubles1 double A double B return A B But something like bool CompareDoubles2 double A double B diff A..
Undefined, unspecified and implementation-defined behavior http://stackoverflow.com/questions/2397984/undefined-unspecified-and-implementation-defined-behavior a string literal is undefined. I can hear people screaming But wait I can compile this no problem and get the output yellow..
http://stackoverflow.com/questions/3106110/what-is-move-semantics rid of the copy by leaving the scope. Nothing new here. But if you say a x y the move constructor will initialize that because..
What is the copy-and-swap idiom? http://stackoverflow.com/questions/3279543/what-is-the-copy-and-swap-idiom bugs such as deleting the array only to try and copy it . But in all other cases it merely serves to slow the program down.. the copy and swap idiom will fix all these issues. But right now we have all the requirements except one a swap function... an in class swap along side a free function swap etc. But this is all unnecessary any proper use of swap will be through..
http://stackoverflow.com/questions/356950/c-functors-and-their-uses creates a function which adds 42 to whatever you give it. But that value 42 is not hardcoded it was specified as a constructor..
Undefined Behavior and Sequence Points http://stackoverflow.com/questions/4176328/undefined-behavior-and-sequence-points to `i` `i` gets modified more than once b w two SP But the following expressions are fine i i i 1 1 well defined AFAIK..
http://stackoverflow.com/questions/4421706/operator-overloading be done by and often is forwarded to plain functions. But it is important that you get this boiler plate code right. If..
What are the differences between pointer variable and reference variable in C++? http://stackoverflow.com/questions/57483/what-are-the-differences-between-pointer-variable-and-reference-variable-in-c are syntactic sugar so easier code to read and write But what are the differences Summary from answers and links below..
http://stackoverflow.com/questions/589575/size-of-int-long-etc the architecture 16 bits 32 bits 64 bits and the compiler. But are there any standards for C I'm using Visual Studio 2008 on..
Where and why do I have to put the “template” and “typename” keywords? http://stackoverflow.com/questions/610245/where-and-why-do-i-have-to-put-the-template-and-typename-keywords to tell the compiler that inUnion is a template id. But where exactly And should it then assume that inUnion is a class.. for example with T f when T is a type template parameter. But for t x f to be a declaration must be written as typename t..
Load an X509 PEM file into Windows CryptoApi http://stackoverflow.com/questions/1231178/load-an-x509-pem-file-into-windows-cryptoapi how to encrypt decrypt once I've got a HCRYPTKEY. BUT I just don't get how to import the Base64 blob in the .PEM file.. c pub.pem GENERIC_READ 0 NULL OPEN_EXISTING FILE_ATTRIBUTE_NORMAL NULL if hFile INVALID_HANDLE_VALUE fprintf stderr Failed..
How do you get the icon, MIME type, and application associated with a file in the Linux Desktop? http://stackoverflow.com/questions/1629172/how-do-you-get-the-icon-mime-type-and-application-associated-with-a-file-in-th is no clear answer seems to be correct as far as it goes. BUT this is such a screwed up situation that I am opening the question..
Symbol not found when using template defined in a library http://stackoverflow.com/questions/18543980/symbol-not-found-when-using-template-defined-in-a-library just come along and put the address of the function in. BUT in your case there is no address. You MUST have the template..
Exporting DLL C++ Class , question about .def file http://stackoverflow.com/questions/186232/exporting-dll-c-class-question-about-def-file linker to create the A A int symbol in the export symbols. BUT as @paercebal states in his comment the manual entry of decorated..
Why aren't pointers initialized with NULL by default? http://stackoverflow.com/questions/1910832/why-arent-pointers-initialized-with-null-by-default premium and the developers do not want to give up either. BUT You can simulate the effect of forcing initialization. Most..
communication between native-app and chrome-extension http://stackoverflow.com/questions/20220668/communication-between-native-app-and-chrome-extension stdout. Extension is using PostMessage This is working... BUT .. When I put my program under continuous while loop the flow..
How to convert CString and ::std::string ::std::wstring to each other? http://stackoverflow.com/questions/258050/how-to-convert-cstring-and-stdstring-stdwstring-to-each-other to std string CString cs Hello std string s LPCTSTR cs BUT std string cannot always construct from a LPCTSTR . i.e. the..
When do C++ POD types get zero-initialized? http://stackoverflow.com/questions/3102096/when-do-c-pod-types-get-zero-initialized point... a is zero f.a is zero c is zero d 0 is zero ... BUT ... b is undefined c constructor initialization share improve..
Creating a transparent window in C++ Win32 http://stackoverflow.com/questions/3970066/creating-a-transparent-window-in-c-win32 simi transparent parts of the PNG show through perfectly. BUT when the background underneath the application changes the background..
What are access specifiers? Should I inherit with private, protected or public? http://stackoverflow.com/questions/5447498/what-are-access-specifiers-should-i-inherit-with-private-protected-or-public as Protected are accessible from outside the class BUT only in a class derived from it. Private These members are only..
profiling: deque is 23% of my runtime http://stackoverflow.com/questions/5574699/profiling-deque-is-23-of-my-runtime tryAsDefine is 23 of my runtime. It took 70secs to run BUT remember profiling is slow. A normal run is about 7 but profiling..
http://stackoverflow.com/questions/586634/shrinking-a-vector When the block increases in detail so the vector does. BUT when the block decreases its detail the vector doesn't shrink..
Getting std :: ifstream to handle LF, CR, and CRLF? http://stackoverflow.com/questions/6089231/getting-std-ifstream-to-handle-lf-cr-and-crlf line getline f line if f.fail a non empty line was read BUT there might be an ' r' at the end now. Edit Thanks to Neil for..
C++ When should we prefer to use a two chained static_cast over reinterpret_cast http://stackoverflow.com/questions/6594395/c-when-should-we-prefer-to-use-a-two-chained-static-cast-over-reinterpret-cast be a huge flashing symbol that says THIS LOOKS CRAZY BUT I KNOW WHAT I'M DOING. Don't use it just out of laziness. reinterpret_cast..
Move semantics & returning const values http://stackoverflow.com/questions/7138780/move-semantics-returning-const-values std string const v char const sep THE FOLLOWING WORKS BUT I THINK THAT IS ACCIDENTAL IT CALLS c_str std string const BUT.. I THINK THAT IS ACCIDENTAL IT CALLS c_str std string const BUT I THINK THE TEMPORARY RETURNED BY my_join v IS NO LONGER ALIVE..
What data structure, exactly, are deques in C++? http://stackoverflow.com/questions/8627373/what-data-structure-exactly-are-deques-in-c a vector perhaps by interpreting it as a circular buffer . BUT A deque must satisfy Inserting a single element either at the..
Unique class type Id that is safe and holds across library boundaries http://stackoverflow.com/questions/922442/unique-class-type-id-that-is-safe-and-holds-across-library-boundaries char s_name return id unique for DERIVED ALWAYS VALID BUT STRING NOT INT BUT VALID AND CROSS PLATFORM CROSS VERSION COMPATBLE.. id unique for DERIVED ALWAYS VALID BUT STRING NOT INT BUT VALID AND CROSS PLATFORM CROSS VERSION COMPATBLE AS FAR AS YOU..
How to load a custom binary resource in a VC++ static library as part of a dll? http://stackoverflow.com/questions/9240188/how-to-load-a-custom-binary-resource-in-a-vc-static-library-as-part-of-a-dll then the static library will be able to find the resource. BUT if the static library is part of a dll and I link it in as an..
QThread ASSERT failure in QMutexLocker: “QMutex pointer is misaligned”, http://stackoverflow.com/questions/9458664/qthread-assert-failure-in-qmutexlocker-qmutex-pointer-is-misaligned QThread 0x4fb2b8 current thread is FileUploader 0x2580748 BUT Just before I start step through the list I print the threadId..
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