VC++ .net: Functionality from managed DLL is not exported
It's public ref class BridgedThirdPartyThing for C++/CLI. You don't use __declspec(dllexport). Note that the class needs to be public to be visible to comsuming assemblies....
How to send enum type to Invoke (delegate) Visual C++
As documented by MSDN Control::Invoke Method (Delegate, array) the Invoke method accepts these parameters: method Type: System::Delegate A delegate to a method that takes parameters of the same number and type that >are contained in the args parameter. args Type: array An array of objects to pass as arguments to...
Add more features to stack container
If this is interview question or something , and you have to do it anyways , you can do this like ,below code . derive from std::stack , and overload [] operator #include <iostream> #include <algorithm> #include <stack> #include <exception> #include <stdexcept> template <typename T> class myStack:public std::stack<T> { public:...
Vector iterator not incremental
The problem with filterByCategory is that the vector fin is empty, you either need to create it with the correct number of elements, or use std::back_inserter to create elements on demand. By the way, there's no need to copy into the all vector first. Use e.g. repo->getAll().begin() directly in the...
How emplace_back() works without variadic templates in Visual Studio 2012?
According to this official list of supported C++11 language features, the variadic templates are not supported in VS 2012. And there is the following note on the same page below: Variadics: Visual C++ in Visual Studio 2012 had a scheme for simulating variadic templates. In Visual C++ in Visual Studio...
Is it possible to override IEnumerable in VC++/CLI?
Yikes, it is an awfully clumsy error message. What it is really complaining about is the missing implementation of the non-generic System::Collections::IEnumerable::GetEnumerator() method. You must implement it because the generic IEnumerable<> interface inherits the non-generic one. Something that made sense when generics were first added in .NET 2.0, not so...
C++ Strings Matching Returning False
You are comparing two pointers, and they will never be the same. Either heed the advice to use std::string (what I recommend too) or you use strcmp to compare strings.
Multiple Key Press handling in mfc
The right way is to handle WM_CUT, WM_COPY and WM_PASTE, because the copy/paste operations could be completed not only Ctrl+C, but CTrl+Insert, and so on ... if you want to handle these things ... "PreTranslateMessage is dangerous territory": really true ! Take care !...
How can I use a variable in another input statement?
else if (isalpha(expr1[i])) { stackIt.push(mapVars1[expr1[i]]); } Will place the variable, or zero if the variable has not been set, onto the stack. else if (isalpha(expr1[i])) { map<char, double>::iterator found = mapVars1.find(expr1[i]); if (found != mapVars1.end()) { stackIt.push(found->second); } else { // error message and exit loop } } Is probably...
What does the thing between “class” and the class name in VC++ mean?
When building a DLL, SomethingStrange will boil down to __declspec(dllexport). When using that DLL, it will boil down to __declspec(dllimport). They allow a class declaration to be used by both the author and users of a particular DLL. What they "boil down to" is normally controlled by compiler flags controlled...
unique_ptr constructor with custom deleter is deleted
This appears to be a defect in the Visual C++ standard library. The unique_ptr class has this constructor for taking a pointer and a deleter: unique_ptr(pointer _Ptr, typename _If<is_reference<_Dx>::value, _Dx, const typename remove_reference<_Dx>::type&>::type _Dt) _NOEXCEPT : _Mybase(_Ptr, _Dt) { // construct with pointer and (maybe const) deleter& } However, the...
Use C++ DLL library project in C++ /CLR project
Does the include file for the unmanaged project include <thread>, directly or indirectly? That's probably the cause of the error. Try to make the interface header of the unmanaged project just define the interface, and not include any implementation-dependent include files....
How to handle an event message while using chrome embedded framework (CEF)?
c++,winapi,visual-c++,chromium-embedded
see CefDoMessageLoopWork(), this is meant to be called from your own message loop. So you could implement your windows message loop and call this on idle. This is from the comment to cef_do_message_loop_work() which is what CefDoMessageLoopWork() calls and gives more information: // Perform a single iteration of CEF message...
Round decimal for a float number
c++,visual-c++,integer,cocos2d-x-3.0
The answer depends on what type do you want the result to be. If you want to obtain the result as float, then this is impossible. From float's point of view, 1.3 and 1.300000000 are exactly the same values and you can not have a float that holds 1.3, not...
How to sync a Progress Control with a set of data which is loading in a Dialog Box in Visual C++
c++,visual-studio-2012,visual-c++,mfc
You should first add a variable for the control, by right-clicking on the progress bar in the dialog editor, and choosing Add Variable... Your dialog class will then have an instance of a CProgressCtrl class on which you can then call the members that IInspectable has mentioned in his answer....
Cannot link to sublibrary/internal library/embedded library with CMake's Visual Studio generator
c++,visual-studio,visual-c++,cmake
From your other question, I gather the project is this one. The cause of the problem is that you're building boost_http as a shared library, but you don't export any functions or classes from it. You need to decorate the public API functions/classes with __declspec(dllexport) to make these available to...
C++, how to call functions when reading their ID number from a Mysql table?
It depends on the type of the function (input/outputs) but assuming they are all the same, you can make an array of function pointers. For example: std::vector<void(*)(int)> MyArray; Will declare an array of function pointers returning void and taking one int as parameter. Then you can put the functions you...
how to print to screen only once in the end of a multiple for tests
As you loop through everything, keep track of both the current max and a list of all configurations that result in the current max. When you find a higher max, clear the list, add the new max's configuration, and continue. In pseudocode, max = 0 configurations = [] for ......
Changing the launch directory of executable in MSVC
c++,c,visual-c++,visual-studio-2013
Go to project properties, Debugging sheet and set 'Working directory' accordingly
What does the * do with that class?
* does not do anything with a class, it changes the type of the declared variable by making it a pointer: ClassA *classa; // classa is a pointer to ClassA You can add multiple asterisks to make pointers to pointers, pointers to pointers to pointers, and so on: ClassA **classa;...
How to use GetFileTime in c++
I tried this code, and it worked. #include <windows.h> #include <stdio.h> int main(void) { HANDLE hFile1; FILETIME ftCreate; SYSTEMTIME stUTC, stLocal; hFile1 = CreateFile("mytestfile.txt", GENERIC_READ, FILE_SHARE_READ, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL); if(hFile1 == INVALID_HANDLE_VALUE) { printf("Could not open file, error %ul\n", GetLastError()); return -1; } if(!GetFileTime(hFile1, &ftCreate, NULL, NULL)) { printf("Something...
Non-managed referenced code strangely, “magically” changes its state for no reason when wrapped in managed
The problem is in: ManagedBar^ ManagedFoo:bar() { ThirdParty::Bar tpb = delegate -> bar(); //for test/debugging: bool b = tpb.shouldBeTrue(); // b is true return gcnew ManagedBar(&tpb); } tpb is destroyed after the function call. You should allocate tpb on the heap(you will need to manually free it), save it somewhere(as...
link.exe returns error LNK1181: cannot open input file 'C:\Program.obj'
c++,windows,visual-c++,linker,linker-error
The problem was with the environment variable link that you used. The MS linker also uses this variable for flags. From https://msdn.microsoft.com/en-us/library/6y6t9esh.aspx: The LINK tool uses the following environment variables: LINK, if defined. The LINK tool processes options and arguments defined in the LINK environment variable before processing the command...
How can i optimize my AVX implementation of dot product?
c,visual-c++,simd,avx,dot-product
There are two big inefficiencies in your loop that are immediately apparent: (1) these two chunks of scalar code: __declspec(align(32)) double ar[4] = { xb[i].x, xb[i + 1].x, xb[i + 2].x, xb[i + 3].x }; ... __m256d y = _mm256_load_pd(ar); and __declspec(align(32)) double arr[4] = { xb[i].x, xb[i + 1].x,...
Which is better for MFC application hot key or Accelerator?
c++,windows,visual-c++,mfc,keyboard-shortcuts
Hotkeys added via RegisterHotKey (or its equivalent in MFC) are definitely system global and you should not use them to trigger functions in your program unless you specifically want the user to be able to trigger them from anywhere. (e.g. your application might be a screenshot app, and so triggering...
Arithmentic operator(+) operator will check both return type and passing arguments or not?
The return type of a function does not participate in overload resolution. Only the function name and parameter list (and cv qualifiers for a member function) matter. But I can see no multiple definition in your code. The error is that you have re-declarations of the same function with different...
Error with construction, unable to find object when calling its method?
c++,visual-c++,constructor,g++,rvalue
Looks like a most vexing parse. The compiler thinks you are declaring a function instead of an object. This also works: int main() { Data<int> a(100); TestClass test = TestClass(DataContainer(a)); std::cout << test.get() << std::endl; return 0; } ...
Static Class Template member initialization
templates,c++11,visual-c++,static,msvc12
Basically, you don't need to put TemplateObj<T>:: before the function definition if it is inside the class definition. The following two are both valid: template<class T> class A{ void func( void ); }; template<class T> void A<T>::func() { /* Okay */ } template<class T> class B { void func( void...
How to initialize a String^ *
You cannot get this going, it is illegal to store managed objects in an unmanaged array. Or to reference them with an unmanaged pointer. The garbage collector can never correctly find the objects back, it must be a managed array. The compiler will not produce a decent error message to...
MFC: How to fix row and column repetition in CListctrl
Is it not that you're simply not clearing the list before refreshing the contents. And it's appending rows and columns again rather than replacing. Call m_list.DeleteAllItems() before refreshing. Update after comment: Right, so that confirms you're refreshing the contents too often or in the wrong place. DeleteAllItems() will clear the...
How to implement an interface defined in VB.net in VC++/CLI?
Looks like you just forgot get(). Proper syntax is: .h file: public ref class ThirdPartyInterfacingBar : Bar { public: property array<Quux^>^ Quuxes { virtual array<Quux^>^ get(); } }; .cpp file: array<Quux^>^ ThirdPartyInterfacingBar::Quuxes::get() { return delegateGetQuuxes(); } ...
MSVC function demangling
As you observed, the claim that a union name X is transformed to [email protected]@ is not a correct description of the name mangling used by your MSVC version. Note that "agner.org" is not associated with Microsoft, and doesn't provide official documentation. As for your question how the different parts of...
Why a breakpoint jumps in my C++ code?
VS behaves differently with C++ and C#. In the case of C++, the debugger will ignore lines that don't contain any actual code and will keep moving the breakpoint until it hits a line that does contain some code. A somewhat related behavior is that if you try to debug...
Dynamic Memory Deletion in vc++
The CString class implements (LPCTSTR) cast operator that you can use to get const TCHAR*. Please note that TCHAR is defined as char in MBCS mode, and as wchar in UNICODE mode. For more details please refer to tchar.h where its defined. If you'd like to modify the content of...
CMFCTabCtrl get handle of tabs and their childs
CMCFTabCtrl is derived from CMFCBaseTabCtrl. You should be using CMFCBaseTabCtrl::GetTabWnd to iterate through the child tabs within your loop. Depending on how you've set up the tabs, you may need to enumerate the child CWnds on the returned CWnd from GetTabWnd.
CInvalidArgumentException when checking class in PreTranslateMessage
CWnd::GetFocus returns a pointer to the window that has the current focus, or NULL if there is no focus window. pControl = this->GetFocus(); if ( pControl != NULL ) { if(!(pControl->IsKindOf(RUNTIME_CLASS(CEdit)))) ... } Another way is to compare pControl value with pointer to CEdit class member (or members) of the...
VC++: how-to convert CString to TCHAR*
CString::GetBuffer() doesn't make any conversion, it gives direct access to string. To make a copy of CString: CString str = TEXT("text"); TCHAR* buf = new TCHAR[str.GetLength()+1]; lstrcpy(buf, str); TRACE(TEXT("%s\n"), buf); delete[]buf; However the above code is usually not useful. You might want to modify it like so: TCHAR* buf =...
C++ Why does this work
c++,visual-studio,visual-c++,switch-statement
Apparently you have leftover input including a newline, in the input buffer of cin. That happens when you use other input operations than getline. They generally don't consume everything in the input buffer. Instead of the extra getline you can use ignore, but better, do that at the place where...
Linker error compiling DX10 program in Visual Studio 2015
visual-studio,visual-c++,linker,directx
Which version of the legacy DirectX SDK are you using? Static libraries* from different versions of the Visual C++ compiler are generally not compatible, so my guess is you are using a DirectX SDK that no longer supports VS 2005--I believe the February 2010 DXSDK was the last one that...
C++ DLL does not run on different machine
On machine it doesnt work open your dll in dependency walker. Examine the out put for errors, it is possible that you are using debug version of your dll which works fine on machine with visual studio or it maybe c++ redistributable which is missing on target machine
Adding to struct from a loop (c++)
c++,visual-c++,for-loop,struct
The problem here is that you are using the [] operator on a type. You declared lines as a struct. (It helps to keep to give your typenames a capital letter so you can differentiate them more easily.) I think you meant to call sub[i].text.
Reading file made by cmd, results in 3 weird symbols
This is almost certainly BOM (Byte Order Mark) : see here, which means that your file is saved in UNICODE with BOM. There is a way to use C++ streams to read files with BOM (you have to use converters) - let me know if you need help with that.
Disable application taskbar icon's context menu in Windows 8.0 and 8.1
windows,winapi,visual-c++,contextmenu,windows-taskbar
I found this registry value which does the job well: NoViewContextMenu: https://technet.microsoft.com/en-us/library/cc960925.aspx...
Difference between vector and list [duplicate]
c++,visual-studio-2012,visual-c++
A vector is a resizable array. It's elements are stored next to each other in a contiguous block of memory, so that the position of each can be calculated quickly; this is known as random access. Inserting and removing elements from the middle requires moving all the later elements, so...
How to use namespace System; in MFC application with VC++
c++,sql,visual-c++,mfc,namespaces
Namespace System is part of the .NET library, which requires you to use the C++/cli or C# language. MFC is a C++ library, programmed with C++. If you are new to all this I do not recommend you attempt to program in two languages. You can find some other way...
Is strtok() safe to use [duplicate]
You can use it, it's a part of the standard library. It uses internal storage that is shared across all users of the function, so no it's not thread-safe. It also modifies the string you hand to it, which is quite scary. I would not recommend using it, in most...
Compile-time error while using custom C++ header file - “std_lib_facilities.h”
Your library "std_lib_facilities.h" is using custom implementation of vector which doesn't have vector<bool> specialized template. The specialized template uses allocator<bool> with vector<bool>::reference as a return value for operator[]. In your case it's using default allocator which is returning std::_Vb_reference<std::_Wrap_alloc<std::allocator<char32_t>>> from operator[] - hence your problem....
msvc++ doesn't see overloaded operator<<
There appears to be some kind of bug with default arguments, overloaded operators, and template function parameter overload resolution. These are all complex, so sort of understandable. The good news is that you shouldn't be taking just any iomanip there -- you should be taking a specific one. You can...
How to zoom in/out an image on clicking zoom in/out button in SDI?
You might want to derive your document view class from CScrollView instead of the default CView created by the wizard. Use the SetScrollSizes() member function to set the zoom level. You could use SetScaleToFit() initially to define 100% zoom. In OnDraw() use CDC::StretchBlt() to actually draw the image to the...
Is there a Visual Studio Project Configuration Macro which defines DEBUG or RELEASE regardless of the Project Configuration Name?
visual-studio,visual-c++,visual-studio-2013,configuration,macros
Property sheets allow you to make 'User Defined Macros', which translate into configuration variables you can use in your project files. You would: Create a two property sheets. In each, create a User Defined Macro (named say ConfigurationType - do not use $ or () when creating it), in one...
VC++/CLI: How to prevent an unmanaged object from being destroyed when it goes out of scope?
c++,.net,visual-c++,c++-cli,interop
You can either change getTheB to return a heap-allocated ClassB, or have ManagedClassB make his own copy of the db object. Update for the copy: I assume ManagedClassB's constructor looks something like public ref class ManagedClassB { public: ManagedClassB(ClassB* p) : m_p(p) { } ... private: ClassB* m_p; }; You...
UCHAR * to CString conversion and CString to UCHAR * to conversion in vc++
Second data may be string or int so how to do conversion in proper way. You have to interpret the UCHAR* data as a proper data type when formatting it, eg: // if pBuffer contains 'int' data... str.format(_T("%d"), *(int*)pBuffer); // if pBuffer contains 8bit 'char' data w/ a null...
Google Chrome - How to compile Google Chrome in Windows?
google-chrome,visual-c++,windows-8.1,ninja
DONE. Windows 8.1 Pro 64-bit. Visual Studio 2013 Community edition Step 1: C:\>mkdir folder C:\>cd folder C:\>unzip https://src.chromium.org/svn/trunk/tools/depot_tools.zip C:\folder>dir Directory of C:\folder 18/04/2015 02:59 <DIR> depot_tools 0 File(s) 0 bytes 3 Dir(s) 67 387 064 320 bytes free Step 2: C:\folder\depot_tools>git config --global user.name "John Doe" C:\folder\depot_tools>git config --global user.email "[email protected]" C:\folder\depot_tools>git config...
Why this causing Heap corruption?
What's wrong with it? It actually goes wrong at strcpy_s. Because strcpy_s overwrites the target buffer first (to the size specified in the function call). See https://msdn.microsoft.com/en-us/library/td1esda9.aspx - The debug versions of these functions first fill the buffer with 0xFE. To disable this behavior, use _CrtSetDebugFillThreshold. (That is quite subtle...
How to handle Key press ctrl+shift+A in sdi mfc
Your first if-clause is true, whether the Shift key is pressed or not, so you'll never reach the else-clause. If you change the order of your statements, you'll get both: case _T( 'A' ): if ( ( GetKeyState( VK_CONTROL ) < 0 ) && ( GetKeyState( VK_SHIFT ) < 0...
Managing code with using #define
As @Paranaix mention you can provide preprocessor definition for compiler as command line argument like -DmyOption. Let suppose you use Visual Studio, you can open project properties->C/C++->Preprocessor->Preprocessor Definitions and place myOption in that list. It automatically add -DmyOption argument for compiler. So every source file in your project now can...
Linq in C++ CLI
xml,linq,visual-c++,xpath,c++-cli
I was able to rewrite your code in such a way: using namespace System; using namespace System::Collections::Generic; using namespace System::Xml::Linq; using namespace System::Xml::XPath; ref class cROI { public: property int iX ; property int iY ; property int iWidth ; property int iHeight; cROI (int piX, int piY,int piWidth,int piHeight...
Why the standard of naming of C++ functions is not exist?
A standard does exist, see https://mentorembedded.github.io/cxx-abi/abi.html#mangling But not all compilers use it, because they have their own mangling conventions that they have used for many years, and they don't want to change them for various reasons. In your case the differences between different versions of Visual Studio are not just...
Cannot link Boost to CMake-based project on VS2015 RC
c++,visual-studio,visual-c++,boost,cmake
The problem is that you define BOOST_TEST_DYN_LINK which according to the Boost.Test docs is used when consuming the dynamically-built Boost.Test lib. Since you have built the static version, you should remove this definition....
WUSA catastrophic failure 0x8000ffff when called from system() VC++
c++,windows,visual-c++,windows-update
I have figured out how to solve this issue and I will post my solution for anyone in the future that has the same issue. The system() command was running the 32-bit executable inside %windir%\SysWoW64\ instead of the native 64-bit version. To solve this issue I had to use the...
Is it possible to change Pictue Control background color istead of Changing image?
You should be painting in OnPaint of the picture control, not OnPaint of the dialog. When you did Add Variable it should have created CStatic m_PictureControlVariable; and added this variable into DoDataExchange. DoDataExchange does the same thing as your call to SubclassDlgItem, so you should remove that redundant call. Now...
Error while calling Select() in UDP sockets
winforms,visual-studio-2010,sockets,select,visual-c++
You probably are "shadowing" the winsock library's function select() by having defined another vaiable with this name. This code #include <Winsock2.h> /* Provide prototype for select(). */ void foo(void) { int select; ... select(0, 0, 0, 0, 0); would provoke error C2064 by "shadowing" the function select() with the variable...
How to find what headers my C++ application is using? [duplicate]
c++,visual-c++,visual-studio-2013
There is a project setting in VS that can do this. Go to the Property Pages for your project, then Configuration Properties | C/C++ | All Options. Enable the Show Includes options. Build your project, and examine output. This is the /showIncludes option.
C++ unsigned long doesn't wrap around after 4294967295
c++,visual-c++,integer,g++,long-integer
if i start a unsigned long with 4294967295 ( his max allowed value ) 4294967295 is only the maximum value for unsigned long if unsigned long is a 32-bit type. This is the case on Windows, both 32-bit and 64-bit. On Linux, unsigned long is a 32-bit type on...
Why is a “user breakpoint” called when I run my project with imported .lib, not when code is inline?
c++,visual-c++,dll,runtime-error,breakpoints
Using complex types such as std::string as a parameter at a DLL boundary is tricky. You must ensure that the exe and the DLL use the exact same instance of the library code. This requires that you build them both to use the same version of the DLL version of...
Windows Service not starting on cold boot
.net,windows,visual-c++,windows-services
There could be a race condition during start up. If the Event Log has not started working before the system attempts to start your service, and there is a dependency on that log, this may cause your service to fail. Perhaps you can Change the order in which your service...
Buttons not getting replaced in CMFCToolbar at runtime
visual-c++,mfc,mfc-feature-pack
This was resolved after calling AdjustLayout after inserting the buttons. The code is as below. void MyClass::ReplaceButtons() { m_m_myMFCToolbar.RemoveAllButtons(); if(condition1) { m_myMFCToolbar.InsertButton( CMFCToolBarButton(ID_BUTTON1, 0, _T("MyText1"), FALSE, TRUE ) ); m_myMFCToolbar.InsertButton( CMFCToolBarButton(ID_BUTTON2, 1, _T("MyText2"), FALSE, TRUE ) ); } else { m_myMFCToolbar.InsertButton( CMFCToolBarButton(ID_BUTTON3, 2, _T("MyText3"), FALSE, TRUE ) ); m_myMFCToolbar.InsertButton( CMFCToolBarButton(ID_BUTTON4,...
MFC: member variable vs resource id of control
The efficient way is to create a control member variable. You can do this in the resource editor by right-click on the control and select Add Variable. Every time you use GetDlgItem with the resource ID then it iterates through all child controls to find the one with the specified...
Should Resource IDs be unique in my shared MFC DLLs
It just depends on the Kind of modules you have. Loading a resource alwway requires a handle where to load it from. If you use extension module DLLs all resource IDs in EXE and DLL must be unique in the MFC. So for Extension modules it doesn't matter where the...
Macro to push arguments onto stack
If you are still interested in tricking the Visual C++ compiler you can try this code #define pushargs(...) for (unsigned int _esp; ;) _esp = varcount(), _esp =(_esp-varcount(__VA_ARGS__))>>2, pushargs_c(_esp, __VA_ARGS__ ); unsigned int __declspec(naked) __forceinline varcount(...) { __asm mov eax, esp; __asm ret; } unsigned int __declspec(naked) __forceinline pushargs_c(unsigned int...
template programming: ambiguous call to overloaded function
c++,templates,c++11,visual-c++
The problem is two fold. First, sort is found via ADL, so you get two overloads, and they both match. In general, naming functions the same as std functions when you are not trying to ADL-overload is fraught, due to the possibility of ADL-induced ambiguity. Now, this only happens when...
How to check/compare whether four variables are same or different using conditional statement in C# or C++
c#,linq,sorting,visual-c++,conditional-statements
To get the number of distinct values: int i = new [] { a, b, c, d }.Distinct().Count(); To get the count of each distinct value: Dictionary<int,int> counts = new [] { a, b, c, d } .GroupBy(t=>t) .ToDictionary(g=>g.Key, g=>g.Count()); This gives you a dictionary that maps each distinct value...
Create string with ESC characters
"\065" does not create "A" but "5". "\065" is interpreted as an octal number, which is decimal 53, which is character '5'. std::string s = "\xc8" ; (hex) gives me the character 200....
Setting timeout to recv function
You should check return value of select. select will return 0 in case timeout expired, so you should check for error and call recv only if select returned positive value: On success, select() and pselect() return the number of file descriptors contained in the three returned descriptor sets (that is,...
Is the author's code correct? - B. Stroustrup's PPP using C++: Chapter 7, Section 7.2 - Input & Output
You are not crazy. It's not unheard of for published books to have bugs. Often times, the corresponding website for a book will have an online "errata" sheet that contains all the corrections pending for the next printing. I just checked. I found a few typos on Stroustrup's website itself....
Linking error using soci 3.2.3 instead of 3.2.2
The Solution was using the newest error corrected Soci library from github and not the stable download version. Bests...
Template specialization static member in different namespace
c++,templates,c++11,visual-c++,gcc
This is a compiler bug, and still present in HEAD. Please report it. Clang provides a clearer diagnostic: error: cannot define or redeclare 'bar' here because namespace 'O' does not enclose namespace 'Foo' const int Baz::bar = 1; ~~~~~^ ...
Unhandled Exception with Binary Search Tree [closed]
If you add a note to an empty BST, the execution will be: bool BST::add(int k, int x, int y) { return add(root, k, x, y); } As root is NULL, the following will happen in add(root, k, x, y): bool success; if (n = NULL) { // <=== OUCH...
Zoom Bitmap Image from center in mfc
Why bother with the m_logoImage: void CRightUp::ImageDraw(int sHeight,int sWidth){ RECT r; GetClientRect(&r); CDC *screenDC = GetDC(); m_img.StretchBlt(screenDC->m_hDC, ((r.right-r.left)-sWidth)/2, ((r.bottom-r.top)-sHeight)/2, sWidth, sHeight, 0, 0, m_img.GetWidth(), m_img.GetHeight(), SRCCOPY); ReleaseDC(screenDC); } This will only paint it for the moment. If you are calling ImageDraw rapidly (say, every 1/10th a second or more), it...
Does C allow casting a struct type to itself?
c,visual-c++,visual-studio-2008,struct
No. The (draft C11) standard text that requires this behavior is in §6.5.4.2: Unless the type name specifies a void type, the type name shall specify atomic, qualified, or unqualified scalar type, and the operand shall have scalar type In other words, you can't cast structs at all. One fix...
Visual Studio 2013 LINK : fatal error LNK1181: cannot open input file
c++,visual-studio,opencv,visual-c++,visual-studio-2013
Remove all references to the library. Somewhere that project is pointing at the path you give above and you need to remove that. Then add the library into the executable project. Right click->add->existing item, change the type to all files, then browse to the file location. ...
I want to be able to use 4 different variables in a select statement in c ++
Those functions build a query string like this: SELECT ..whatever.. FROM ..whatever.. WHERE ... \ ... and [WORKORDER_SUB_ID] LIKE 'wid' and [RESOURCE_ID] LIKE 'rid' and ... ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~ ^ build by setSubID ^ build by setResourceID ^ by other you need to build this: ... and [WORKORDER_SUB_ID] LIKE 'wid'...
How to convert CString to long? VC++
As mentioned earlier, you are using Unicode. You have to use Unicode for other functions: long ldata = _wtol(str); Somewhere inside CString declarations is something like this: #ifdef UNICODE #define CString CStringW #else #define CString CStringA #endif When project is compiled as Unicode, CString becomes wide char CStringW, so you...
Why does C++ allow a semicolon at the start of a line? [duplicate]
This is the C and C++ standards for NOP (short for No Operation). The simplest possible statement in C/C++ that behaves like a NOP is the so-called null statement, which is just a semi-colon in a context requiring a statement. (A compiler is not required to generate a NOP instruction...
Building in VC6, need unsigned long long
__int64 is a vendor-specific base type. It can be combined with the unsigned modifier, just like: unsigned char unsigned __int8 unsigned short unsigned __int16 unsigned int unsigned __int32 unsigned long unsigned __int32 (unsigned long long) unsigned __int64 (unsigned __int128) Where the parenthesized names are not available in VC6, but are...
Visual C++ accepts One point decimal
Before adding the point, check the text to see if it already contains a point. if ((lblDatos->TextLength > 0) && !(lblDatos->Text->Contains(".")) { lblDatos->Text = lblDatos->Text + "."; } ...
std::map for small sparse collections
c++,visual-studio-2010,visual-c++
The memory overhead of a map isn't that bad. It's typically a few words per node. Using a map to start with would definitely be OK under the "no premature optimization" rule. That said, when you do optimize, the map will be high on the list of data structures to...
Using C callback in C++/CLI
illegal operation on bound member function expression This looks like you are attempting to callback a class member function. It can be done, but is a little tricky. You are best to callback a free global function, get it working, then look into how to call back a class member...
How to enable user to re-entry(or) reuse the same dialog in MFC
Here is what you need to do: You should make CInternetSession m_Session; a member of your CWinApp-derived class. You should call m_Session.Close() in ExitInstance() method of your CWinApp-derived class. In your CDialog-derived class you should only deal with CFtpConnection related stuff. So when user clicks on Download button you should...
C++ How to create byte[] array from file (I don't mean reading file byte by byte)?
int t194(void) { // imagine you have n pair of char, for simplicity, // here n is 3 (you should recognize them) char pair1[] = "01"; // note: char pair2[] = "8c"; // initialize with 3 char c-style strings char pair3[] = "c7"; // { // let us put these...
In VC++, is there any way to know the export class of a dll without any header files?
The closest you can get is by reverse engineering (use a debugger) to find the required memory size before calling a constructor, and maybe you could figure out what members are used for (as well as inheritance and other goodies), but you will definitely not have correct names for anything...
Very first build error after installing Visual Studio 2013. fatal error LNK1561: entry point must be defined
c++,visual-c++,visual-studio-2013
I think you may change it to: #include <iostream> using namespace std; //class Source{ int main() { cout << "out" << endl; return 0; } //}; ...
Program hangs in Visual Studio debugger
c++,visual-studio,c++11,visual-c++
This issue is caused by an OS scheduler bug introduced in the spring 2014 update to Windows 8.1. A hotfix for this problem was released in May 2015 and available at https://support.microsoft.com/en-us/kb/3036169.