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  • Enumeration trouble: redeclared as different kind of symbol

    - by Matt
    Hello all. I am writing a program that is supposed to help me learn about enumeration data types in C++. The current trouble is that the compiler doesn't like my enum usage when trying to use the new data type as I would other data types. I am getting the error "redeclared as different kind of symbol" when compiling my trangleShape function. Take a look at the relevant code. Any insight is appreciated! Thanks! (All functions are their own .cpp files.) header file #ifndef HEADER_H_INCLUDED #define HEADER_H_INCLUDED #include <iostream> #include <iomanip> using namespace std; enum triangleType {noTriangle, scalene, isoceles, equilateral}; //prototypes void extern input(float&, float&, float&); triangleType extern triangleShape(float, float, float); /*void extern output (float, float, float);*/ void extern myLabel(const char *, const char *); #endif // HEADER_H_INCLUDED main function //8.1 main // this progam... #include "header.h" int main() { float sideLength1, sideLength2, sideLength3; char response; do //main loop { input (sideLength1, sideLength2, sideLength3); triangleShape (sideLength1, sideLength2, sideLength3); //output (sideLength1, sideLength2, sideLength3); cout << "\nAny more triangles to analyze? (y,n) "; cin >> response; } while (response == 'Y' || response == 'y'); myLabel ("8.1", "2/11/2011"); return 0; } triangleShape shape # include "header.h" triangleType triangleShape(sideLenght1, sideLength2, sideLength3) { triangleType triangle; return triangle; }

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  • Template trick to optimize out allocations

    - by anon
    I have: struct DoubleVec { std::vector<double> data; }; DoubleVec operator+(const DoubleVec& lhs, const DoubleVec& rhs) { DoubleVec ans(lhs.size()); for(int i = 0; i < lhs.size(); ++i) { ans[i] = lhs[i]] + rhs[i]; // assume lhs.size() == rhs.size() } return ans; } DoubleVec someFunc(DoubleVec a, DoubleVec b, DoubleVec c, DoubleVec d) { DoubleVec ans = a + b + c + d; } Now, in the above, the "a + b + c + d" will cause the creation of 3 temporary DoubleVec's -- is there a way to optimize this away with some type of template magic ... i.e. to optimize it down to something equivalent to: DoubleVec ans(a.size()); for(int i = 0; i < ans.size(); i++) ans[i] = a[i] + b[i] + c[i] + d[i]; You can assume all DoubleVec's have the same # of elements. The high level idea is to have do some type of templateied magic on "+", which "delays the computation" until the =, at which point it looks into itself, goes hmm ... I'm just adding thes numbers, and syntheizes a[i] + b[i] + c[i] + d[i] ... instead of all the temporaries. Thanks!

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  • How can variadic char template arguments from user defined literals be converted back into numeric types?

    - by Pubby
    This question is being asked because of this one. C++11 allows you to define literals like this for numeric literals: template<char...> OutputType operator "" _suffix(); Which means that 503_suffix would become <'5','0','3'> This is nice, although it isn't very useful in the form it's in. How can I transform this back into a numeric type? This would turn <'5','0','3'> into a constexpr 503. Additionally, it must also work on floating point literals. <'5','.','3> would turn into int 5 or float 5.3 A partial solution was found in the previous question, but it doesn't work on non-integers: template <typename t> constexpr t pow(t base, int exp) { return (exp > 0) ? base * pow(base, exp-1) : 1; }; template <char...> struct literal; template <> struct literal<> { static const unsigned int to_int = 0; }; template <char c, char ...cv> struct literal<c, cv...> { static const unsigned int to_int = (c - '0') * pow(10, sizeof...(cv)) + literal<cv...>::to_int; }; // use: literal<...>::to_int // literal<'1','.','5'>::to_int doesn't work // literal<'1','.','5'>::to_float not implemented

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  • Compile time type determination in C++

    - by dicroce
    A coworker recently showed me some code that he found online. It appears to allow compile time determination of whether a type has an "is a" relationship with another type. I think this is totally awesome, but I have to admit that I'm clueless as to how this actually works. Can anyone explain this to me? template<typename BaseT, typename DerivedT> inline bool isRelated(const DerivedT&) { DerivedT derived(); char test(const BaseT&); // sizeof(test()) == sizeof(char) char (&test(...))[2]; // sizeof(test()) == sizeof(char[2]) struct conversion { enum { exists = (sizeof(test(derived())) == sizeof(char)) }; }; return conversion::exists; } Once this function is defined, you can use it like this: #include <iostream> class base {}; class derived : public base {}; class unrelated {}; int main() { base b; derived d; unrelated u; if( isRelated<base>( b ) ) std::cout << "b is related to base" << std::endl; if( isRelated<base>( d ) ) std::cout << "d is related to base" << std::endl; if( !isRelated<base>( u ) ) std::cout << "u is not related to base" << std::endl; }

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  • Howcome some C++ functions with unspecified linkage build with C linkage?

    - by christoffer
    This is something that makes me fairly perplexed. I have a C++ file that implements a set of functions, and a header file that defines prototypes for them. When building with Visual Studio or MingW-gcc, I get linking errors on two of the functions, and adding an 'extern "C"' qualifier resolved the error. How is this possible? Header file, "some_header.h": // Definition of struct DEMO_GLOBAL_DATA omitted DWORD WINAPI ThreadFunction(LPVOID lpData); void WriteLogString(void *pUserData, const char *pString, unsigned long nStringLen); void CheckValid(DEMO_GLOBAL_DATA *pData); int HandleStart(DEMO_GLOBAL_DATA * pDAta, TCHAR * pLogFileName); void HandleEnd(DEMO_GLOBAL_DATA *pData); C++ file, "some_implementation.cpp" #include "some_header.h" DWORD WINAPI ThreadFunction(LPVOID lpData) { /* omitted */ } void WriteLogString(void *pUserData, const char *pString, unsigned long nStringLen) { /* omitted */ } void CheckValid(DEMO_GLOBAL_DATA *pData) { /* omitted */ } int HandleStart(DEMO_GLOBAL_DATA * pDAta, TCHAR * pLogFileName) { /* omitted */ } void HandleEnd(DEMO_GLOBAL_DATA *pData) { /* omitted */ } The implementations compile without warnings, but when linking with the UI code that calls these, I get a normal error LNK2001: unresolved external symbol "int __cdecl HandleStart(struct _DEMO_GLOBAL_DATA *, wchar_t *) error LNK2001: unresolved external symbol "void __cdecl CheckValid(struct _DEMO_MAIN_GLOBAL_DATA * What really confuses me, now, is that only these two functions (HandleStart and CheckValid) seems to be built with C linkage. Explicitly adding "extern 'C'" declarations for only these two resolved the linking error, and the application builds and runs. Adding "extern 'C'" on some other function, such as HandleEnd, introduces a new linking error, so that one is obviously compiled correctly. The implementation file is never modified in any of this, only the prototypes.

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  • Improving File Read Performance (single file, C++, Windows)

    - by david
    I have large (hundreds of MB or more) files that I need to read blocks from using C++ on Windows. Currently the relevant functions are: errorType LargeFile::read( void* data_out, __int64 start_position, __int64 size_bytes ) const { if( !m_open ) { // return error } else { seekPosition( start_position ); DWORD bytes_read; BOOL result = ReadFile( m_file, data_out, DWORD( size_bytes ), &bytes_read, NULL ); if( size_bytes != bytes_read || result != TRUE ) { // return error } } // return no error } void LargeFile::seekPosition( __int64 position ) const { LARGE_INTEGER target; target.QuadPart = LONGLONG( position ); SetFilePointerEx( m_file, target, NULL, FILE_BEGIN ); } The performance of the above does not seem to be very good. Reads are on 4K blocks of the file. Some reads are coherent, most are not. A couple questions: Is there a good way to profile the reads? What things might improve the performance? For example, would sector-aligning the data be useful? I'm relatively new to file i/o optimization, so suggestions or pointers to articles/tutorials would be helpful.

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  • add uchar values in ushort array with sse2 or sse3

    - by pompolus
    i have an unsigned short dst[16][16] matrix and a larger unsigned char src[m][n] matrix. Now i have to access in the src matrix and add a 16x16 submatrix to dst, using sse2 or ss3. In a my older implementation, I was sure that my summed values ??were never greater than 256, so i could do this: for (int row = 0; row < 16; ++row) { __m128i subMat = _mm_lddqu_si128(reinterpret_cast<const __m128i*>(src)); dst[row] = _mm_add_epi8(dst[row], subMat); src += W; // Step to next row i need to add } where W is an offset to reach the desired rows. This code works, but now my values in src are larger and summed could be greater than 256, so i need to store them as ushort. i've tried this: for (int row = 0; row < 16; ++row) { __m128i subMat = _mm_lddqu_si128(reinterpret_cast<const __m128i*>(src)); dst[row] = _mm_add_epi16(dst[row], subMat); src += W; // Step to next row i need to add } but it doesn't work. I'm not so good with sse, so any help will be appreciated.

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  • Generating authentication header from azure table through objective-c

    - by user923370
    I'm fetching data from iCloud and for that I need to generate a header (azure table storage). I used the code below for that and it is generating the headers. But when I use these headers in my project it is showing "make sure that the value of authorization header is formed correctly including the signature." I googled a lot and tried many codes but in vain. Can anyone kindly please help me with where I'm going wrong in this code. -(id)generat{ NSString *messageToSign = [NSString stringWithFormat:@"%@/%@/%@", dateString,AZURE_ACCOUNT_NAME, tableName]; NSString *key = @"asasasasasasasasasasasasasasasasasasasasas=="; const char *cKey = [key cStringUsingEncoding:NSUTF8StringEncoding]; const char *cData = [messageToSign cStringUsingEncoding:NSUTF8StringEncoding]; unsigned char cHMAC[CC_SHA256_DIGEST_LENGTH]; CCHmac(kCCHmacAlgSHA256, cKey, strlen(cKey), cData, strlen(cData), cHMAC); NSData *HMAC = [[NSData alloc] initWithBytes:cHMAC length:sizeof(cHMAC)]; NSString *hash = [Base64 encode:HMAC]; NSLog(@"Encoded hash: %@", hash); NSURL *url=[NSURL URLWithString: @"http://my url"]; NSMutableURLRequest *request = [NSMutableURLRequest requestWithURL:url]; [request addValue:[NSString stringWithFormat:@"SharedKeyLite %@:%@",AZURE_ACCOUNT_NAME, hash] forHTTPHeaderField:@"Authorization"]; [request addValue:dateString forHTTPHeaderField:@"x-ms-date"]; [request addValue:@"application/atom+xml, application/xml"forHTTPHeaderField:@"Accept"]; [request addValue:@"UTF-8" forHTTPHeaderField:@"Accept-Charset"]; NSLog(@"Headers: %@", [request allHTTPHeaderFields]); NSLog(@"URL: %@", [[request URL] absoluteString]); return request; } -(NSString*)rfc1123String:(NSDate *)date { static NSDateFormatter *df = nil; if(df == nil) { df = [[NSDateFormatter alloc] init]; df.locale = [[[NSLocale alloc] initWithLocaleIdentifier:@"en_US"] autorelease]; df.timeZone = [NSTimeZone timeZoneWithAbbreviation:@"GMT"]; df.dateFormat = @"EEE',' dd MMM yyyy HH':'mm':'ss 'GMT'"; } return [df stringFromDate:date]; }

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  • overloading "<<" with a struct (no class) cout style

    - by monkeyking
    I have a struct that I'd like to output using either 'std::cout' or some other output stream. Is this possible without using classes? Thanks #include <iostream> #include <fstream> template <typename T> struct point{ T x; T y; }; template <typename T> std::ostream& dump(std::ostream &o,point<T> p) const{ o<<"x: " << p.x <<"\ty: " << p.y <<std::endl; } template<typename T> std::ostream& operator << (std::ostream &o,const point<T> &a){ return dump(o,a); } int main(){ point<double> p; p.x=0.1; p.y=0.3; dump(std::cout,p); std::cout << p ;//how? return 0; } I tried different syntax' but I cant seem to make it work.

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  • C++ class with char pointers returning garbage

    - by JMP
    I created a class "Entry" to handle Dictionary entries, but in my main(), I create the Entry() and try to cout the char typed public members, but I get garbage. When I look at the Watch list in debugger, I see the values being set, but as soon as I access the values, there is garbage. Can anyone elaborate on what I might be missing? #include <iostream> using namespace std; class Entry { public: Entry(const char *line); char *Word; char *Definition; }; Entry::Entry(const char *line) { char tmp[100]; strcpy(tmp, line); Word = strtok(tmp, ",") + '\0'; Definition = strtok(0,",") + '\0'; } int main() { Entry *e = new Entry("drink,What you need after a long day's work"); cout << "Word: " << e->Word << endl; cout << "Def: " << e->Definition << endl; cout << endl; delete e; e = 0; return 0; }

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  • c++ specialized overload?

    - by acidzombie24
    -edit- i am trying to close the question. i solved the problem with boost::is_base_and_derived In my class i want to do two things. 1) Copy int, floats and other normal values 2) Copy structs that supply a special copy function (template T copyAs(); } the struct MUST NOT return int's unless i explicitly say ints. I do not want the programmer mistaking the mistake by doing int a = thatClass; -edit- someone mention classes dont return anything, i mean using the operator Type() overload. How do i create my copy operator in such a way i can copy both 1) ints, floats etc and the the struct restricted in the way i mention in 2). i tried doing template <class T2> T operator = (const T2& v); which would cover my ints, floats etc. But how would it differentiate from structs? so i wrote T operator = (const SomeGenericBase& v); The idea was the GenericBase would be unsed instead then i can do v.Whatever. But that backfires bc the functions i want wouldnt exist, unless i use virtual, but virtual templates dont exist. Also i would hate to use virtual I think the solution is to get rid of ints and have it convert to something that can do .as(). So i wrote something up but now i have the same problem, how does that differentiate ints and structs that have the .as() function template?

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  • Handling Apache Thrift list/map Return Types in C++

    - by initzero
    First off, I'll say I'm not the most competent C++ programmer, but I'm learning, and enjoying the power of Thrift. I've implemented a Thrift Service with some basic functions that return void, i32, and list. I'm using a Python client controlled by a Django web app to make RPC calls and it works pretty well. The generated code is pretty straight forward, except for list returns: namespace cpp Remote enum N_PROTO { N_TCP, N_UDP, N_ANY } service Rcon { i32 ping() i32 KillFlows() i32 RestartDispatch() i32 PrintActiveFlows() i32 PrintActiveListeners(1:i32 proto) list<string> ListAllFlows() } The generated signatures from Rcon.h: int32_t ping(); int32_t KillFlows(); int32_t RestartDispatch(); int32_t PrintActiveFlows(); int32_t PrintActiveListeners(const int32_t proto); int64_t ListenerBytesReceived(const int32_t id); void ListAllFlows(std::vector<std::string> & _return); As you see, the ListAllFlows() function generated takes a reference to a vector of strings. I guess I expect it to return a vector of strings as laid out in the .thrift description. I'm wondering if I am meant to provide the function a vector of strings to modify and then Thrift will handle returning it to my client despite the function returning void. I can find absolutely no resources or example usages of Thrift list< types in C++. Any guidance would be appreciated.

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  • VC9 C1083 Cannot open include file: 'boost...' after trying to abstract an include dependency

    - by ronivek
    Hey, So I've been working on a project for the past number of weeks and it uses a number of Boost libraries. In particular I'm using the boost::dynamic_bitset library quite extensively. I've had zero issues up until now; but tonight I discovered a dependency between some includes which I had to resolve; and I tried to do so by providing an abstract callback class. Effectively I now have the following: First include... class OtherClassCallback { public: virtual int someOtherMethod() const = 0; }; class SomeClass { public: void someMethod(OtherClassCallback *oc) { ... oc->someOtherMethod(); ... } }; Second include... #include "SomeClass.h" class SomeOtherClass : public OtherClassCallback { public: int someOtherMethod() const { return this->someInt; } }; Here is the issue; ever since I implemented this class I'm now getting the following error: fatal error C1083: Cannot open include file: 'boost/dynamic_bitset/dynamic_bitset.hpp': No such file or directory Now I'm getting no other compiler errors; and it's a pretty substantial project. My include paths and so on are perfect; my files are fully accessible and removing the changes fixes the issue. Does anyone have any idea what might be going on? I'm compiling to native Windows executables in VS9. I should confess that I'm very inexperienced with C++ in general so go easy on me if it's something horribly straightforward; I can't figure it out.

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  • C++ design question, container of instances and pointers

    - by Tom
    Hi all, Im wondering something. I have class Polygon, which composes a vector of Line (another class here) class Polygon { std::vector<Line> lines; public: const_iterator begin() const; const_iterator end() const; } On the other hand, I have a function, that calculates a vector of pointers to lines, and based on those lines, should return a pointer to a Polygon. Polygon* foo(Polygon& p){ std::vector<Line> lines = bar (p.begin(),p.end()); return new Polygon(lines); } Here's the question: I can always add a Polygon (vector Is there a better way that dereferencing each element of the vector and assigning it to the existing vector container? //for line in vector<Line*> v //vcopy is an instance of vector<Line> vcopy.push_back(*(v.at(i)) I think not, but I dont really like that approach. Hopefully, I will be able to convince the author of the class to change it, but I cant base my coding right now to that fact (and i'm scared of a performance hit). Thanks in advance.

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  • C++ design question, container of instances and pointers

    - by Tom
    Hi all, Im wondering something. I have class Polygon, which composes a vector of Line (another class here) class Polygon { std::vector<Line> lines; public: const_iterator begin() const; const_iterator end() const; } On the other hand, I have a function, that calculates a vector of pointers to lines, and based on those lines, should return a pointer to a Polygon. Polygon* foo(Polygon& p){ std::vector<Line> lines = bar (p.begin(),p.end()); return new Polygon(lines); } Here's the question: I can always add a Polygon (vector Is there a better way that dereferencing each element of the vector and assigning it to the existing vector container? //for line in vector<Line*> v //vcopy is an instance of vector<Line> vcopy.push_back(*(v.at(i)) I think not, but I dont really like that approach. Hopefully, I will be able to convince the author of the class to change it, but I cant base my coding right now to that fact (and i'm scared of a performance hit). Thanks in advance.

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  • C++ design question, container of instances and pointers

    - by Tom
    Hi all, Im wondering something. I have class Polygon, which composes a vector of Line (another class here) class Polygon { std::vector<Line> lines; public: const_iterator begin() const; const_iterator end() const; } On the other hand, I have a function, that calculates a vector of pointers to lines, and based on those lines, should return a pointer to a Polygon. Polygon* foo(Polygon& p){ std::vector<Line> lines = bar (p.begin(),p.end()); return new Polygon(lines); } Here's the question: I can always add a Polygon (vector Is there a better way that dereferencing each element of the vector and assigning it to the existing vector container? //for line in vector<Line*> v //vcopy is an instance of vector<Line> vcopy.push_back(*(v.at(i)) I think not, but I dont really like that approach. Hopefully, I will be able to convince the author of the class to change it, but I cant base my coding right now to that fact (and i'm scared of a performance hit). Thanks in advance.

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  • C++: Copy contructor: Use Getters or access member vars directly?

    - by cbrulak
    Have a simple container class: public Container { public: Container() {} Container(const Container& cont) //option 1 { SetMyString(cont.GetMyString()); } //OR Container(const Container& cont) //option 2 { m_str1 = cont.m_str1; } public string GetMyString() { return m_str1;} public void SetMyString(string str) { m_str1 = str;} private: string m_str1; } So, would you recommend this method or accessing the member variables directly? In the example, all code is inline, but in our real code there is no inline code. Update (29 Sept 09): Some of these answers are well written however they seem to get missing the point of this question: this is simple contrived example to discuss using getters/setters vs variables initializer lists or private validator functions are not really part of this question. I'm wondering if either design will make the code easier to maintain and expand. Some ppl are focusing on the string in this example however it is just an example, imagine it is a different object instead. I'm not concerned about performance. we're not programming on the PDP-11

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  • std::stringstream GCC Abnormal Behavior

    - by FlorianZ
    I have a very interesting problem with compiling a short little program on a Mac (GCC 4.2). The function below would only stream chars or strings into the stringstream, but not anything else (int, double, float, etc.) In fact, the fail flag is set if I attempt to convert for example an int into a string. However, removing the preprocessor flag: _GLIBCXX_DEBUG=1, which is set by default in XCode for the debug mode, will yield the desired results / correct behavior. Here is the simple function I am talking about. value is template variable of type T. Tested for int, double, float (not working), char and strings (working). template < typename T > const std::string Attribute<T>::getValueAsString() const { std::ostringstream stringValue; stringValue << value; return stringValue.str(); } Any ideas what I am doing wrong, why this doesn't work, or what the preprocessor flag does to make this not work anymore? Thanks!

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  • C++ Template problem adding two data types

    - by Sara
    I have a template class with an overloaded + operator. This is working fine when I am adding two ints or two doubles. How do I get it to add and int and a double and return the double? template <class T> class TemplateTest { private: T x; public: TemplateTest<T> operator+(const TemplateTest<T>& t1)const { return TemplateTest<T>(x + t1.x); } } in my main function i have void main() { TemplateTest intTt1 = TemplateTest<int>(2); TemplateTest intTt2 = TemplateTest<int>(4); TemplateTest doubleTt1 = TemplateTest<double>(2.1d); TemplateTest doubleTt2 = TemplateTest<double>(2.5d); std::cout << intTt1 + intTt2 << /n; std::cout << doubleTt1 + doubleTt2 << /n; } I want to be able to also do this std::cout << doubleTt1 + intTt2 << /n;

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  • Clicking the mouse down to drag objects on Mac

    - by Uri
    I've been using the following code to issue clicks programmatically on a Mac void PostMouseEvent(CGMouseButton button, CGEventType type, const CGPoint point) { CGEventRef theEvent = CGEventCreateMouseEvent(NULL, type, point, button); CGEventSetType(theEvent, type); CGEventPost(kCGHIDEventTap, theEvent); CFRelease(theEvent); } void Click(const CGPoint point) { PostMouseEvent(kCGMouseButtonLeft, kCGEventMouseMoved, point); NSLog(@"Click!"); PostMouseEvent(kCGMouseButtonLeft, kCGEventLeftMouseDown, point); PostMouseEvent(kCGMouseButtonLeft, kCGEventLeftMouseUp, point); } Now, I'm trying to click down to be able to drag objects, like a scroll bar or an application's window. I'm using the following: PostMouseEvent(kCGMouseButtonLeft, kCGEventMouseMoved, point); NSLog(@"Click Down!"); PostMouseEvent(kCGMouseButtonLeft, kCGEventLeftMouseDown, point); When i ran the code above something interesting will happen, when the left mouse down is issue nothing seem to happen, I move my mouse and the window doesn't move, however when I added a mouse up event then the window jumped to the location where I supposedly dragged it. this is sort of OK, however, how do I can make the mouse click down and drag an object? Note: I do have a whole method to see when the mouse stopped moving so I can click up. please post code. Thanks

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  • How to Populate a 'Tree' structure 'Declaratively'

    - by mackenir
    I want to define a 'node' class/struct and then declare a tree of these nodes in code in such a way that the way the code is formatted reflects the tree structure, and there's not 'too much' boiler plate in the way. Note that this isn't a question about data structures, but rather about what features of C++ I could use to arrive at a similar style of declarative code to the example below. Possibly with C++0X this would be easier as it has more capabilities in the area of constructing objects and collections, but I'm using Visual Studio 2008. Example tree node type: struct node { string name; node* children; node(const char* name, node* children); node(const char* name); }; What I want to do: Declare a tree so its structure is reflected in the source code node root = node("foo", [ node("child1"), node("child2", [ node("grand_child1"), node("grand_child2"), node("grand_child3" ]), node("child3") ]); NB: what I don't want to do: Declare a whole bunch of temporary objects/colls and construct the tree 'backwards' node grandkids[] = node[3] { node("grand_child1"), node("grand_child2"), node("grand_child3" }; node kids[] = node[3] { node("child1"), node("child2", grandkids) node("child3") }; node root = node("foo", kids);

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  • streaming xml pretty printer in C/C++ using expat or libxml2?

    - by Mark Zeren
    I have a library that outputs xml without whitespace all on one line. In some cases I'd like to pretty print that output. I'm looking for a BSD-ish licensed C/C++ library or sample code that will take a raw xml byte stream and pretty print it. Here's some pseudo code showing one way that I might use this functionality: void my_write(const char* buf, int len); PrettyPrinter pp(bind(&my_write)); while (...) { // ... get some more xml ... const char* buf = xmlSource.get_buf(); int len = xmlSource.get_buf_len(); int written = pp.write(buf, len); // calls my_write with pretty printed xml // ... error handling, maybe call write again, etc. ... } I'd like to avoid instantiating a DOM representation. I already have dependencies on the expat and libxml2 shared libraries, and I'd rather not add any more shared library dependencies.

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  • What is the purpose of the QAbstractButton::checkStateSet() method?

    - by darkadept
    I'm writing my own 4 state button and I'm not quite sure what to put in the checkStateSet() method, if anything. Here is what I've got so far: SyncDirectionButton::SyncDirectionButton(QWidget *parent) : QAbstractButton(parent) { setCheckable(true); setToolTip(tr("Click to change the sync direction")); _state = NoSync; } void SyncDirectionButton::paintEvent(QPaintEvent *e) { static QPixmapCache::Key noneKey; static QPixmapCache::Key bothKey; static QPixmapCache::Key leftKey; static QPixmapCache::Key rightKey; QPainter p(this); QPixmap pix; if (checkState() == SyncLeft) { if (!QPixmapCache::find(leftKey, &pix)) { pix.load(":/icons/sync-left.png"); leftKey = QPixmapCache::insert(pix); } } else if (checkState() == SyncBoth) { if (!QPixmapCache::find(rightKey, &pix)) { pix.load(":/icons/sync-right.png"); rightKey = QPixmapCache::insert(pix); } } else if (checkState() == SyncRight) { if (!QPixmapCache::find(bothKey, &pix)) { pix.load(":/icons/sync-both.png"); bothKey = QPixmapCache::insert(pix); } } else if (checkState() == NoSync) { if (!QPixmapCache::find(noneKey, &pix)) { pix.load(":/icons/application-exit.png"); noneKey = QPixmapCache::insert(pix); } } p.drawPixmap(0,0,pix); } SyncDirectionButton::DirectionState SyncDirectionButton::checkState() const { return _state; } void SyncDirectionButton::setCheckState(DirectionState state) { setChecked(state != NoSync); if (state != _state) { _state = state; } } QSize SyncDirectionButton::sizeHint() const { return QSize(180,90); } void SyncDirectionButton::checkStateSet() { } void SyncDirectionButton::nextCheckState() { setCheckState((DirectionState)((checkState()+1)%4)); }

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  • Search string in file (C)

    - by chutsu
    So my code isn't working... test.c:27: warning: passing argument 1 of ‘search’ from incompatible pointer type which is the fgets line. My code opens a file, reads the file line by line, and I'm trying to create a "search" function that will return a value that indicates whether that string is found on that line of the file. My ultimate goal is to achieve a search and replace program. But one step at a time eh? this is what I have so far: #include <stdio.h> #include <string.h> int search(const char *content[], const char *search_term) { int t; for(t=0; content[t]; ++t){ if(!strcmp(content[t], search_term)){ return t; // found } } return 0; // not found } int main(int argc, char *argv[]) { FILE *file; char line[BUFSIZ]; int linenumber=0; char term[20] = "hello world"; file = fopen(argv[1], "r"); if(file != NULL){ while(fgets(line, sizeof(line), file)){ if(search(line, term) != -1){ printf("Search Term Found!!\n"); } ++linenumber; } } else{ perror(argv[1]); } fclose(file); return 0; }

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  • Compile C++ in Visual Studio

    - by Kasun
    Hi All.. I use this method to compile C++ file in VS. But even i provide the correct file it returns false. Can any one help me... This is class called CL class CL { private const string clexe = @"cl.exe"; private const string exe = "Test.exe", file = "test.cpp"; private string args; public CL(String[] args) { this.args = String.Join(" ", args); this.args += (args.Length > 0 ? " " : "") + "/Fe" + exe + " " + file; } public Boolean Compile(String content, ref string errors) { if (File.Exists(exe)) File.Delete(exe); if (File.Exists(file)) File.Delete(file); File.WriteAllText(file, content); Process proc = new Process(); proc.StartInfo.UseShellExecute = false; proc.StartInfo.RedirectStandardOutput = true; proc.StartInfo.RedirectStandardError = true; proc.StartInfo.FileName = clexe; proc.StartInfo.Arguments = this.args; proc.StartInfo.CreateNoWindow = true; proc.Start(); //errors += proc.StandardError.ReadToEnd(); errors += proc.StandardOutput.ReadToEnd(); proc.WaitForExit(); bool success = File.Exists(exe); return success; } } This is my button click event private void button1_Click(object sender, EventArgs e) { string content = "#include <stdio.h>\nmain(){\nprintf(\"Hello world\");\n}\n"; string errors = ""; CL k = new CL(new string[] { }); if (k.Compile(content, ref errors)) Console.WriteLine("Success!"); else MessageBox.Show("Errors are : ", errors); }

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