i am just making some new programmings and testing it. But every time after compile and run The dos window is closing and again I have to compile And run command so i want The dos windows should prompt me for next input rather than closing.
I need to have an object of class A that doesn't have a default constructor in another class, B:
Code: class A; //This is in a separate header file class B { private:A a;};
The problem is that it won't compile without a default constructor. I'm not allowed to define a default constructor, and the A object in class B has to be private so I can't initialize A a in public.
I also can't change the prototype in the interface to something like
A(int a = 0, int b = 0);
since one of the requirements is that if an object of class A is declared in main, it must not compile due to not having a default constructor. So what can I do to make class B work and compile?
Another question I have is why is this valid:
Code: class A; //#include "A.h" is in the implementation file so it compiles. class B { private:A* a;}; But not this: Code: class A;
class B { private:A a;};
This is for a project that I probably won't be able to turn in on time, but I care more about how to do this right than turning it in for full points.
I am working on one application that requires extensive logging so I want to create a log file of each day during execution.
I tried easylogging++ but i am unable to use into multiple files. If i try to use in other file. I get compilation errors of using same functions or methods already defined.
How can i use macro to hide the implementation of logging in one class to other ??
I've been writing a game engine in C++ for a little over a year now, and its been really fun so far. I've been focusing on windows support for now (using Visual Studio and MSVC) but I'd like to leave the possibility of Linux and Mac support open. As a test, I recently compiled a small portion of my reflection system in Clang, to make sure it all still worked (since I consider that the most advanced portion of my codebase, though I'm pretty sure its all standard C++11). Anyway, I got some strange errors regarding undefined identifiers in template functions, and I managed to isolate the issue in the code below:
Clang throws an error about 'TypeInfo' being undefined when 'DoSomething()' is compiled. However, MSVC compiles the code above without so much as a warning.
This goes against my understanding of how template functions/classes were compiled. I always thought that Undefined symbols were not an issue in templates, as long as they were defined by the time the template was instantiated. Whats the issue here? If in fact MSVC has been doing some non-standard stuff, that's pretty unfortunate for me if I want Linux support, as I'll have to do some serious backflips to resolve all the issues with this in my headers and stuff (I can't be the only one in thinking the current state of C++ with headers and forward-decelerations is just awful to work with).
I want to do conditional compilation based on whether it is windows 7 or windows 8. Here is the code below.
#if (_WIN32_WINNT >= 0x0602) //Condition to check whether it windows 7 or 8 .Based on this we can load msxml 3 or 6. #import <msxml6.dll> #else #import <msxml3.dll> #endif
Im building the above code in windows 8 machine.
Issue here is _WIN32_WINNT should have a value 0x0602, it means it is running in windows 8 machine.Instead it has a value 0x0601 (Means it is taking windows version as windows 7 defined in sdkddkver.h).Im not sure after installing windows 8 sdk im not able to see any include or lib files in the path below C:Program Files (x86)Microsoft SDKsWindowsv8.0A . but i can see all include and lib files of sdk version v7.0A available although i did not installed it.
This is my question : Define a class named HOUSING in C++ with the following descriptions:
Private members REG_NO integer(Ranges 10 - 1000) NAME Array of characters(String) TYPE Character COST Float
Public Members -Function Read_Data( ) to read an object of HOUSING type -Function Display() to display the details of an object -Function Draw Nos( ) to choose and display the details of 2 houses selected randomly from an array of 10 objects of type HOUSING Use random function to generate the registration nos. to match with REGNO from the array.
Now I' trying to do this by this way
Code: #include <iostream.h> #include <conio.h> #include <stdlib.h> class housing { private: int REG_NO; char NAME[10];
[Code] .....
I am trying to pass the entire array of object in DrawNos(). but getting compilation error -
32: 'housing:rawNos(housing * *)' is not a member of 'housing' 48: Structure required on left side of . or .*
What is the problem? How can I pass the array of object in function and use it.
Today I experienced a very strange compiler issue. I started the compilation and it outputted that a member object of a class was undefined. After about 4 hours of trying the find the bug I commented and then uncommented said line of code that was undefined. Sure enough the compilation worked just from commenting and uncommenting.
I am using Microsoft visual studio 2012 express. Due to the size of the project, I should know the cause because it may cause more problems further down the line. I feel that it might have something to do with the compiler not having a proper order of compilation for the header files and that I might need something to solidify the way that the header files are processed. The below code is a fragment of a header file.
I'm parsing a text file, and I'd like to detect when a certain Compilation Condition - i.e. #ifdef - begins. The challenge is, that the condition can take any of the following patterns:
#ifdef (FLAG) #if defined (FLAG) #if (defined (FLAG))
(And perhaps I missed more)
I'd of course need to treat them all the same, as they are indeed the same. How would you know to treat them all the same?
I've been reading about libraries; How to make them, how to use them, the different types of libraries, etc..
When using a shared library, does the program require that library to be installed on the computer after the program has been compiled into an .exe?
Ie.. if somebody downloaded a "Helloworld.exe" that I had compiled on my computer using a shared library (that wasn't part of a standard operating system), would they also need that shared library on their computer for the program to run without errors?
and for Static Libraries, when I compile a program using a static library, does it include in the final binary only the functions of the library that are actually used, or does the compiler add in the entire library?
I am trying to write a generic linked list in c, but for some reason i keep getting errors saying "incompatible pointer type. This is the code and erros:
#include <stdio.h> main() { int c, n1; n1 = 0; while ((c = getchar()) != EOF) if (c == '') ++n1; printf("%d", n1); }
I have a more complicated program I'm wishing to have display the output, however, to save some time I'm using an example of a shorter version. count the lines in input and display the output in terminal when ./program is executed after compilation. To count and compute lines, words and within arrays.
I'm trying out the gmp library by building a simple pi calculation program (original, I know!). On a million digits of Pi I've debugged the program and seem to have about a megabyte too much of memory at the end of the program (I start with around 250k before any allocation begins and end at around 1200).
int main(int argc, char *argv[]) { //set a// int digitsofpi =1000000; mpf_set_default_prec(log2(10) *digitsofpi );
I have been trying to find a way around the following:
I am using a library functor to solve the root of a non linear equation. It passes two doubles and the name of a function that contains the equation to be solved.
I use the library opensteer, but I do not know where you should start.
Opensteer is a library written in C ++. My problem is figuring out whether to create a blank project in visual studio and import the library or directly import the library.
I'm attempting to write a little UDP socket library in c++ on linux so a user can just create a new instance of a UDPSocket class, specify destination ip and port, and just connect. Then the user should be able to call send() or receive() in any order they want.. and here I encounter a little problem..
Most of the tutorials for udp socket sending out there include a bind() call when you create your "server" that is supposed to receive data, but the code that send data does not need one. Because I also want my library to support unicast/broadcast/multicast, I have read that I need to set the socket option SO_REUSEADDR on my sockets (since multiple sockets will need to be connected to same destination IP/port for broadcast/multicast)
My question is.. do I need to create 2 socket handles per "UDPSocke in order to make this work? One for sending and one for receiving data? In my code when I try to work with only 1 socket, it is only able to receive stuff from itself on unicast.. Or should I just remove the SO_REUSEADDR when in unicast mode, then try to bind with both sockets, accept that the bind will only work on the 1st socket, and take it from there?
I want to create a C library function that i can directly call in my code from any .c file having main program.following are codes...code of library function "foo.c"
Code:
#include "foo.h" int foo(int x) /* Function definition */ { return x + 5; } header file "foo.h"
Code:
#ifndef FOO_H_ /* Include guard */ #define FOO_H_ int foo(int x); /* An example function declaration */ }
[code]....
to use this i have to compile the file in below manner...
Code: gcc -o my_app main.c foo.c
My concern here is that i want to compile the main.c and use function without compiling foo.c with i.e.
Code: gcc -o my_app main.c
any user of this function should only compile his program and should be able to use the function, the foo.c file should remain hidden from him
my system is Linux 2.6.18-308.4.1.el5 #1 SMP Wed Mar 28 01:54:56 EDT 2012 x86_64 x86_64 x86_64 GNU/Linux
I am trying to refresh my memory here as I did some studies many years ago but the results elude me.Also todays c/c++ compilers may have better optimizations.Say I have a static library that includes three obj modules.Each of these object modules has a number of functions. These functions do not reference any other functions within the obj module.My main app links this library but only references one function from each of the object modules.
Question: Are the complete contents of each module linked into my main app or are todays linkers smart enough to just link the functions used?
I am in try to use PlPlot library (for plotting) in C with code::blocks IDE (ver 10.05) on windows-7 plateform. I downloaded "plplot-5.9.9.tar" and unzipped it. In documentation it is not very clear to me (I am not expert in using third party lib.), how this library can be used with code::blocks i.e. where I have to save the lib, what should be added in compiler and debugger settings etc. It also seems from document that "makefile" (linux type!!) is necessary for Windows also? I am also unaware of MSYS makefile generator (given on Wiki page) on windows?