Search Results

Search found 2912 results on 117 pages for 'std tr1'.

Page 82/117 | < Previous Page | 78 79 80 81 82 83 84 85 86 87 88 89  | Next Page >

  • What does the C++ compiler error "looks like a function definition, but there is no parameter list;"

    - by SkyBoxer
    #include <iostream> #include <fstream> using namespace std; int main { int num1, num2; ifstream infile; ostream outfile; infile.open("input.dat"); outfile.open("output.dat"); infile >> num 1 >> num 2; outfile << "Sum = " << num1 + num2 << endl; infile.close() outfile.close() return 0; } This is what I did and when I compile it, I got this error that said error C2470: 'main' : looks like a function definition, but there is no parameter list; skipping apparent body Please don't hate me :( I am new at this computer science....

    Read the article

  • HowTo parse numbers from string with BOOST methods?

    - by mosg
    Problem: Visual C++ 10 project (using MFC and Boost libraries). In one of my methods I'm reading simple test.txt file. Here is what inside of the file (std::string): 12 asdf789, 54,19 1000 nsfewer:22!13 Then I'm reading it and I have to convert all digits to int only with boost methods. For example, I have a list of different characters which I have to parse: ( ’ ' ) ( [ ], ( ), { }, ? ? ) ( : ) ( , ) ( ! ) ( . ) ( - ) ( ? ) ( ‘ ’, “ ”, « » ) ( ; ) ( / ) And after conversation I must have some kind of a massive of int's values, like this one: 12,789,54,19,1000,22,13 Maybe some one already did this job? PS. I'm new for boost. Thanks!

    Read the article

  • C++ Pointers to functions.

    - by Andy Leman
    using namespace std; int addition (int a, int b) { return (a+b); } int subtraction (int a, int b) { return (a-b); } int operation (int x, int y, int (*functocall)(int,int)) { int g; g = (*functocall)(x,y); return(g); } int main() { int m,n; int (*minus)(int,int) = subtraction; m = operation (7,5,addition); n = operation (20,m,minus); cout << n; return 0; } Can anybody explain this line for me int (*minus)(int,int) = subtraction; Thanks a lot!

    Read the article

  • Why do I get corrupt output on my file?

    - by Martin
    I have a simple program which I have compiled in both MinGW and Visual C++ 2008 Express, and both give an output file larger than 88200. When I set s = 0, both programs work as expected. What am I doing wrong? #include <fstream> using namespace std; int main(int argc, char *argv[]) { int i; short s; fstream f; f.open("test.raw", ios_base::out); for(i = 0; i < 44100; i++) { s = i & 0xFFFF; // PROBLEM? f.write(reinterpret_cast<const char *>(&s), sizeof(s)); } f.close(); return 0; }

    Read the article

  • pointer delegate in STL set.

    - by ananth
    hi. Im kinda stuck with using a set with a pointer delegate. my code is as follows: void Graph::addNodes (NodeSet& nodes) { for (NodeSet::iterator pos = nodes.begin(); pos != nodes.end(); ++pos) { addNode(*pos); } } Here NodeSet is defined as: typedef std::set NodeSet; The above piece of code works perfectly on my windows machine, but when i run the same piece of code on a MAC, it gives me the following error: no matching function for call to 'Graph::addNode(const boost::shared_ptr&)' FYI, Node_ptr is of type: typedef boost::shared_ptr Node_ptr; can somebody plz tell me why this is happening?

    Read the article

  • How do i use 'auto' in C++ (C++0x) ?

    - by LoudNPossiblyRight
    What do i have to do to this code to make it compile, it's braking around this line: auto val = what.getObject(); #include<iostream> using namespace std; class CUP{ public: void whatsHappening(){} }; class MUG{ public: void whatsHappening(){} }; class CupThrower{ public: CUP cp; CUP getObject(){ return cp;} }; class MugThrower{ public: MUG mg; MUG getObject(){return mg;} }; template <typename T> void whatsHappening(T what){ auto val = what.getObject(); //DOES NOT COMPILE val.whatsHappening(); } int main(){ CupThrower ct; MugThrower mt; whatsHappening(ct); whatsHappening(mt); return 0; } i am using VS2008 to compile.

    Read the article

  • OpenCv not initializing usb camera

    - by brainbarshan
    I am trying to capture video from usb camera using OpenCv. #include <highgui.h> #include <iostream> using namespace std; using namespace cv ; int main() { VideoCapture cap (-1); if(!cap.isOpened()) cout << "Cam initialize failed" ; else cout << "Cam initialized" ; return 0; } It is failing to initialize the camera. cap.isOpened() is returning zero. The same program, with same version of OpenCv and same usb camera, is correctly running in my friend's machine. I am running fedora 16. I did some searching in Google and Stack Overflow. But no useful help. Any idea ?

    Read the article

  • Determining which video format to use

    - by pcasa
    I want to upload a video file and convert it to flash and 3gp/mp4. No problem, plenty of tuts for this out there using paperclip and ffmpeg. For some reason I thought there was a tut that showed if std browser play flv but if mobile then use 3gp/mp4 but can't seem to find it. Any one know if there is a tut like this out there? Else, Can I tell paperclip which is flv and 3gp/mp4. Then later call something in the view like video_url(:flv) or video_url(:mp4) or set this globally if mobile?

    Read the article

  • Possible for C++ template to check for a function's existence?

    - by andy
    Is it possible to write a C++ template that changes behavior depending on if a certain member function is defined on a class? Here's a simple example of what I would want to write: template<class T> std::string optionalToString(T* obj) { if (FUNCTION_EXISTS(T->toString)) return obj->toString(); else return "toString not defined"; } So if class T has "toString" defined then it uses it, otherwise it doesn't. The magical part that I don't know how to do is the "FUNCTION_EXISTS" part.

    Read the article

  • C++: conjunction of binds?

    - by Helltone
    Suppose the following two functions: #include <iostream> #include <cstdlib> // atoi #include <cstring> // strcmp #include <boost/bind.hpp> bool match1(const char* a, const char* b) { return (strcmp(a, b) == 0); } bool match2(int a, const char* b) { return (atoi(b) == a); } Each of these functions takes two arguments, but can be transformed into a callable object that takes only one argument by using (std/boost)bind. Something along the lines of: boost::bind(match1, "a test"); boost::bind(match2, 42); I want to be able to obtain, from two functions like these that take one argument and return bool, a callable object that takes two arguments and returns the && of the bools. The type of the arguments is arbitrary. Something like an operator&& for functions that return bool.

    Read the article

  • Output Unicode to Console Using C++

    - by Jesse Foley
    I'm still learning C++, so bear with me and my sloppy code. The compiler I use is Dev C++. I want to be able to output Unicode characters to the Console using cout. Whenver i try things like: # #include directive here (include iostream) using namespace std; int main() { cout << "Hello World!\n"; cout << "Blah blah blah some gibberish unicode: ÐAßGg\n"; system("PAUSE"); return 0; } It outputs strange characters to the console, like µA¦Gg. Why does it do that, and how can i get to to display ÐAßGg? Or is this not possible with Windows?

    Read the article

  • Whats wrong with the following code, its not compiling

    - by Ganesh Kundapur
    #include <iostream> #include <vector> using namespace std; class Base { public: void Display( void ) { cout<<"Base display"<<endl; } int Display( int a ) { cout<<"Base int display"<<endl; return 0; } }; class Derived : public Base { public: void Display( void ) { cout<<"Derived display"<<endl; } }; void main() { Derived obj; obj.Display(); obj.Display( 10 ); } $test1.cpp: In function ‘int main()’: test1.cpp:35: error: no matching function for call to ‘Derived::Display(int)’ test1.cpp:24: note: candidates are: void Derived::Display() On commenting obj.Display(10), it works.

    Read the article

  • testing directory S_ISDIR acts inconsistently

    - by coubeatczech
    hi, I'm doing simple tests on all files in directory. But from some reason, sometimes, they behave wrongly? What's bad with my code? using namespace std; int main() { string s = "/home/"; struct dirent * file; DIR * dir = opendir(s.c_str()); while ((file = readdir(dir)) != NULL){ struct stat * file_info = new (struct stat); stat(file-d_name,file_info); if ((file_info-st_mode & S_IFMT) == S_IFDIR) cout << "dir" << endl; else cout << "other" << endl; } closedir(dir); }

    Read the article

  • How to test if a string has a certain unicode char?

    - by Ruben Trancoso
    Supose you have a command line executable that receives arguments. This executalbe is widechar ready and you want to test if one of this arguments starts with an HYPHEN case in which its an option: command -o foo how you could test it inside your code if you don't know the charset been used by the host? Should be not possible to a given console to produce the same HYPHEN representation by another char in the widechar forest? (in such case it would be a wild char :P) int _tmain(int argc, _TCHAR* argv[]) { std::wstring inputFile(argv[1]); if(inputFile->c_str() <is an HYPHEN>) { _tprintf(_T("First argument cannot be an option")); } }

    Read the article

  • How to switch iostream from binary to text mode and vice versa?

    - by Mad Fish
    I want to read both formatted text and binary data from the same iostream. How can I do that? Why? Imagine this situation: You have different resources, and resource loaders for them, that take a std::istream as a parameter. And there are a "resource source" that provides these streams. Resources can be both text and binary and I need to handle both cases with resource loaders. Or other situation: Image that you have an archive with resources of mixed types. How can I get a text stream from inside the binary archive stream?

    Read the article

  • What is a good standard for code width?

    - by BillyONeal
    Hello everyone :) I've heard in several places that it's bad to have code that is too wide onscreen. For example: for (std::vector<EnumServiceInformation>::const_iterator currentService = services.begin(); currentService != services.end(); currentService++) However, I've heard many arguments for 80 character wide limits. I'm assuming this 80 character limit comes from the traditional command prompt, which is typically 80 characters wide. However -- most of us are working on something much better than a typical command prompt, and I feel that using an 80 character limit encourages use of variable names that are far too short and do not describe what the variable is used for. What is a reasonable limit for a new project with no existing coding width standard?

    Read the article

  • C++ - Print Out Objects From Set

    - by John Smith
    If I have a C++ set, declaration set personList; with iterator, set::const_iterator location; how can I print out the contents of the set? They are all person objects, and I have overridden the operator<< for Person. The line that errors is: cout << location and it's in a basic for loop. Netbeans gives the following error: proj.cpp:78: error: no match for ‘operator<<’ in ‘std::cout << location’ so it looks like it wants an override for the iterator's <<. Basically, I am taking objects that used to be stored in an array format, but are now in a set. What is the equivalent to cout << array[i] for sets?

    Read the article

  • Using C++ is a Linked-List implementation without using pointers possible or not?

    - by sonicoder
    My question is very simply, can one using C++, implment a link-list data structure without using pointers (next nodes)? To further qualify my question, I'm mean can one create a Linked-List data structure using only class instantiations. A common node definition might be like so: template<typename T> struct node { T t; node<T>* next; node<T>* prev; }; I'm aware of std::list etc, I'm just curious to know if its possible or not - and if so how? code examples will be greatly appreciated.

    Read the article

  • why this signal handler is called infinitely

    - by lz_prgmr
    I am using Mac OS 10.6.5, g++ 4.2.1. And meet problem with following code: #include <iostream> #include <sys/signal.h> using namespace std; void segfault_handler(int signum) { cout << "segfault caught!!!\n"; } int main() { signal(SIGSEGV, segfault_handler); int* p = 0; *p = 100; return 1; } It seems the segfault_handler is called infinitely and keep on print: segfault caught!!! segfault caught!!! segfault caught!!! ... I am new to Mac development, do you have any idea on what happened?

    Read the article

  • Multithreading with STL container

    - by Steven
    I have an unordered map which stores a pointer of objects. I am not sure whether I am doing the correct thing to maintain the thread safety. typedef std::unordered_map<string, classA*>MAP1; MAP1 map1; pthread_mutex_lock(&mutexA) if(map1.find(id) != map1.end()) { pthread_mutex_unlock(&mutexA); //already exist, not adding items } else { classA* obj1 = new classA; map1[id] = obj1; obj1->obtainMutex(); //Should I create a mutex for each object so that I could obtain mutex when I am going to update fields for obj1? pthread_mutex_unlock(&mutexA); //release mutex for unordered_map so that other threads could access other object obj1->field1 = 1; performOperation(obj1); //takes some time obj1->releaseMutex(); //release mutex after updating obj1 }

    Read the article

  • C++ WIN32: Short multitasking example

    - by Con Current
    I searched for examples on how to create a simple multithreaded app that does something similar to this: #include <iostream> using namespace std; int myConcurrentFunction( ) { while( 1 ) { cout << "b" << endl; } } int main( ) { // Start a new thread for myConcurrentFunction while( 1 ) { cout << "a" << endl; } } How can I get the above to output a and b "randomly" by starting a new thread instead of just calling myConcurrentFunction normally? I mean: What is the minimal code for it? Is it really only one function I have to call? What files do I need to include? I use MSVC 2010, Win32

    Read the article

  • boost timer usage question

    - by stefita
    I have a really simple question, yet I can't find an answer for it. I guess I am missing something in the usage of the boost timer.hpp. Here is my code, that unfortunately gives me an error message: include <boost/timer.hpp> int main() { boost::timer t; } And the error messages are as follows: /usr/include/boost/timer.hpp: In member function ‘double boost::timer::elapsed_max() const’: /usr/include/boost/timer.hpp:59: error: ‘numeric_limits’ is not a member of ‘std’ /usr/include/boost/timer.hpp:59: error: ‘::max’ has not been declared /usr/include/boost/timer.hpp:59: error: expected primary-expression before ‘double’ /usr/include/boost/timer.hpp:59: error: expected `)' before ‘double’ The used library is boost 1.36 (SUSE 11.1). Thanks in advance!

    Read the article

  • C++ Boost bind value type

    - by aaa
    hello. I look in documentation and source code but cannot figure out how to get return value type of boost bind functor. I am trying to accomplish following: 35 template<typename T,size_t N, class F> 36 boost::array<typename F::value_type, N> make_array(T (&input)[N], F unary) { 37 boost::array<typename F::value_type, N> array; 38 std::transform(input, input + N, array.begin(), unary); 39 return array; 40 } where F can be bind functor. the above does not work because functor does not have value_type. for that matter, is there standard interface for unary/binary functor as far as return value. Thanks

    Read the article

  • Why isn't the copy constructor elided here?

    - by Jesse Beder
    (I'm using gcc with -O2.) This seems like a straightforward opportunity to elide the copy constructor, since there are no side-effects to accessing the value of a field in a bar's copy of a foo; but the copy constructor is called, since I get the output meep meep!. #include <iostream> struct foo { foo(): a(5) { } foo(const foo& f): a(f.a) { std::cout << "meep meep!\n"; } int a; }; struct bar { foo F() const { return f; } foo f; }; int main() { bar b; int a = b.F().a; return 0; }

    Read the article

  • C++ cin returns 0 for integer no matter what the user inputs

    - by kevin dappah
    No matter the cin it continues to to output 0 for score. Why is that? I tried returning the "return 0;" but still no go :/ #include "stdafx.h" #include <iostream> using namespace std; // Variables int enemiesKilled; const int KILLS = 150; int score = enemiesKilled * KILLS; int main() { cout << "How many enemies did you kill?" << endl; cin >> enemiesKilled; cout << "Your score: " << score << endl; return 0; }

    Read the article

< Previous Page | 78 79 80 81 82 83 84 85 86 87 88 89  | Next Page >