I can't seem to figure out the syntax for finding structs in containers. I have a multiset of Event structs. I'm trying to find one of these structs by searching on its key. I get the compiler error commented below. struct Event { public: bool operator < ( const Event & rhs ) const { return ( time < rhs.time ); } bool operat...
hi, how does header including in c++ work? I have the classes already implemented in .h file and when there is #include in two files, there's this error: files.h:14:7: error: redefinition of ‘class abstract_file’ files.h:14:20: error: previous definition of ‘class abstract_file’` multiple times for each class and enum. Can anyone expl...
I have three files: Main, slist.h and slist.cpp can be seen at http://forums.devarticles.com/c-c-help-52/confused-why-i-am-getting-c2143-and-c1010-error-259574.html I'm trying to make a program where main reads the list of student names from a file (roster.txt) and inserts all the names in a list in ascending order. This is the full cl...
I have a couple c++ utilities that I would like to port over to dot net. I was wondering if there are tools for porting a c++ application to c#? I imagine that any automated tool would make a mess of any code, so perhaps, I should also be asking if this is a good idea or not? ...
Why does class A; template<typename T> class B { private: A* a; public: B(); }; class A : public B<int> { private: friend B<int>::B<int>(); int x; }; template<typename T> B<T>::B() { a = new A; a->x = 5; } int main() { return 0; } result in ../src/main.cpp:15: error: invalid use of constructor ...
I'm very interested in the user-space RCU (read-copy-update), and trying to simulate one via tr1::shared_ptr, here is the code, while I'm really a newbie in concurrent programming, would some experts help me to review? The basic idea is, reader calls get_reading_copy() to gain the pointer of current protected data (let's say it's gener...
Hi, I am new to hardware programming(especially USB) so please bear with me and my questions. I am using C++ and I need to send/receive some data (a byte array) to/from a USB port on a microprocessor board. Now, I have done some serial port programming before and I know that for a serial port you have to open a port, setup, perfor...
I'm wondering if anyone can explain the following to me: If I write int i = 0; float* pf = i; I get a compile error (gcc 4.2.1): error: invalid conversion from ‘int’ to ‘float*’ Makes sense - they are obviously two completely different types. But if instead I write const int i = 0; float* pf = i; It compiles without error. Wh...
Hi, I have a parent form, with some child windows (not forms - just windows, for example label controls) inside it. Under certain circumstances, I want one of those child windows to be drawn "above" the others, to display a message over the entire main form. I've tried setting HWND_TOPMOST and HWND_TOP on the child windows, but it does...
#include "iostream" #include "string" using namespace std; #define AA(bb) \ string(::##bb); int main (int argc, char *argv[]) { AA(aa); } This gives me a bunch of errors but I am trying to understand this error pre.cpp:11:1: error: pasting "::" and "aa" does not give a valid prepr...
Just a quick question. I'm making a web application where C++ communicates with a php script over HTTP Requests/Response. The data being set back and forth is quite small ~36 bytes. But I plan to have many computers connected, contacting the server quite often. I did the math, and I could potentially have gigabytes of data transfer a mon...
Let's say I have ten child windows within a form. How do I make sure one of those windows is drawn over all the others? For example, how do I make sure that window 6 always overdraws windows 1-5 and 7-10? I don't want the window to be drawn over everything else on the screen, just everything else within that form. I've already tried usi...
Yes this is a homework/lab assignment. I am interesting in coming up with/finding an algorithm (I can comprehend :P) for using "backtracking" to solve the subset sum problem. Anyone have some helpful resources? I've spent the last hour or so Googling with not much like finding something I think I could actually use. xD Thanks SO! ...
Hi. I'm working with strings in C++. I recently came across a problem when entering strings. I'm using cin >> string; to get my string as user input. When the user enters a space into the string, the next input is automatically filled out with the remaining letters, or sometimes left blank. As the next input string is often an integer, t...
I have the following operator defined in a C++ class called StringProxy: operator std::string&() { return m_string; } a) What is this and how does this work? I understand the idea of operator overloading, but they normally look like X operator+(double i). b) Given an instance of StringProxy, how can I use this operator to get the...
Title pretty much covers it. If I've added say 3 objects to a list and the list goes out of scope and dies, will it call delete on each entry before going out of scope? Pretty sure yes, but getting tired and need a sanity check. ...
Is there any way of telling istream to keep going until it hits \n instead of normal white space and with out the use of getline and also keeping any format options in the stream? Thanks. ...
I have an online repository with some .h and .cpp files that make up part of a project. I'm trying to check these out and use them in a new project, but am getting errors (C4627 and C1010). All the files have been added to the project (with Add>Existing Item...), and the subdirectories that contain these files have been added to the "Add...
I am looking to define a template class whose template parameter will always be an integer type. The class will contain two members, one of type T, and the other as the unsigned variant of type T -- i.e. if T == int, then T_Unsigned == unsigned int. My first instinct was to do this: template <typename T> class Range { typedef unsign...
I have an application which does some socket communication with some hardwares. Assume for the particular hardware i have an object and this object initiates a thread which listens on a particular port number say 5001 infinitely until a connection is established. Now if i delete this obect is there anyway by which i can ensure that the ...