I've been a C++ developer since it arrived. All was on windows, and I haven't touched it in about 6 years.
Now I'm trying to get an old code-base working using VS Code on my Mac. I'm using clang++ with c++17.
This problem is vexing; I've seen many other posts with the same issue, but the problem always seemed to be something in the code.
Note: this code worked fine with C++11 on Windows.
To simplify, I copied the code to execute right at the top of main. Here is is:
ifstream file("assets/textures/blocks.txt", ios::in);
if( file.is_open() ) {
string s;
getline(file, s); // <-- This line causes the error.
cout << s << endl;
}
As this code worked elsewhere, I assume I've got a setup or environment problem and am looking for hints towards what to check on.
Thank you for any help!
An update:
Thank you. I paired the program down and tried a few things. Here's the deal:
If I leave all my files to be compiled, but replace main.cpp with the below code, the cout line generates the same exception.
If I cull all the unused files, the code works.
Something in some other file is somehow breaking the stream code. I'm clueless.
#include <iostream>
#include <istream>
using namespace std;
int main() // int argc, char** argv)
{
cout << "Hello World" << endl;
}
I should add: this is a GLFW 3D game engine app. It does not subclass or interact with any stream in any way other than the most basic file read/write operations.
I am learning c++ from scratch and I was trying to make hello world program with this code:
#include <iostream>
using namespace std;
int main()
{
cout << "Hello World" << endl;
return 0;
}
but I always end with "this project is out of date"
and when I try to build it I have this error message:
unable to start program 'c:\users\User\documents\visualstudio2012\projects\Consoleapplication3\Debug\ConsoleApplication3.exe'.
the system cannot find the file specified
Your program should fail if you do not include your default #include <iostream>, which implies that your code should be something like this:
#include <iostream>
using namespace std;
int main()
{
cout << "Hello World" << endl;
return 0;
}
These said, to fix your problem, look in the solution explorer box to the left. Make sure that there is actually a .cpp file there. You can do the same by looking the .cpp file where the .sln file for the project is stored. If there is not one, then you will get that error.
When adding a cpp file you want to use the "add new item" icon. (top left with a gold star on it, hover over it to see the name) For some reason Ctrl+N does not actually add a .cpp file to the project.
Sources : System cannot find specified file
I'm following some C++ tutorials and have started experimenting with structures, however a test structure I built is not behaving as intended. I have tried running it a few times and all it outputs is (11db), and when I try rerunning it I get a window saying that the product is already running.
Here is the code...
#include <iostream>
using namespace std;
int main(){
struct Address {
int streetNum;
string streetName;
};
Address myHouse;
myHouse.streetNum = 911;
myHouse.streetName = "Inverness Street";
cout << myHouse.streetName << endl;
return 0;
}
I would expect the output to be "Inverness Street". Why am I getting an error instead?
EDIT ** Bonus points for anyone who can tell me how to remove a missing file warning? I removed a useless file that was created as a means to find my way around creating different types of files, but since I deleted it I have had a warning in the file that it once shared a folder with.
Hi I am just starting to learn C++. I bought this big C++ for Dummies book and have been going through it. Its been really interesting so far but now I am stuck. I have been googling this problem, but to no avail. I am using I am using codeblocks 10.05 with GNU GCC.
I keep getting an error that says:
In function 'main':
undefined reference to 'SafeCracker(int)'
The code isn't complicated. I am just new and am extremely frustrated. I don't want to skip over this part; I want to know what is going on.
Main:
#include <iostream>
#include "safestuff.h"
using namespace std;
int main()
{
cout << "Surprise, surprise!" << endl;
cout << "The combination is (once again)" << endl;
cout << SafeCracker(12) << endl;
return 0;
}
Function:
#include <iostream>
using namespace std;
string SafeCracker(int SafeID)
{
return "13-26-16";
}
Header:
using namespace std;
#ifndef SAFESTUFF_H_INCLUDED
#define SAFESTUFF_H_INCLUDED
string SafeCracker(int SafeID);
#endif // SAFESTUFF_H_INCLUDED
You are not compiling the second file you listed along with the first one. Try compiling directly with gcc to understand this.
assuming your files are named:
main.cpp
SafeCracker.cpp
safestuff.h
This is what you are doing
gcc main.cpp
While you should be doing this
gcc main.cpp SafeCracker.cpp
Also, SafeCracker.cpp should be including the header file as well, just for clarity. Any reasons why you have them separated?
On another note, from seeing Daniel Hu's answer, <iostream> is automatically including <string> for you. You should not depend on this functionality, and should instead include <string> in each file that uses strings.
(From comment below)
You're probably trying to build your main.cpp as a stand-alone file. This will leave SafeCracker.cpp uncompiled. What you need is create a project in Codeblocks and add all three files to it (both *.cpp files as well as the *.h file).
I think it's because you did not #include <string>
C++ has to import the string library to use strings or else everything is treated as char arrays.
I am working on the 'driver' part of my programing assignment and i keep getting this absurd error:
error C2065: 'cout' : undeclared identifier
I have even tried using the std::cout but I get another error that says:
IntelliSense: namespace "std" has no member "cout"
When I have declared using namespace std, included iostream and I even tried to use ostream
#include <iostream>
using namespace std;
int main () {
cout << "hey" << endl;
return 0;
}
I'm using Visual Studio 2010 and running Windows 7. All of the .h files have using namespace std and include iostream and ostream.
In Visual Studio you must #include "stdafx.h" and be the first include of the cpp file. For instance:
These will not work.
#include <iostream>
using namespace std;
int main () {
cout << "hey" << endl;
return 0;
}
#include <iostream>
#include "stdafx.h"
using namespace std;
int main () {
cout << "hey" << endl;
return 0;
}
This will do.
#include "stdafx.h"
#include <iostream>
using namespace std;
int main () {
cout << "hey" << endl;
return 0;
}
Here is a great answer on what the stdafx.h header does.
write this code, it works perfectly..
#include "stdafx.h"
#include <iostream>
using namespace std;
int main()
{
cout<<"Hello World!";
return 0;
}
I had same problem on Visual Studio C++ 2010. It's easy to fix. Above the main() function just replace the standard include lines with this below but with the pound symbol in front of the includes.
# include "stdafx.h"
# include <iostream>
using namespace std;
The include "stdafx.h" is ok
But you can't use cout unless you have included using namespace std
If you have not included namespace std you have to write std::cout instead of simple cout
If the only file you include is iostream and it still says undefined, then maybe iostream doesn't contain what it's supposed to. Is it possible that you have an empty file coincidentally named "iostream" in your project?
I have seen that if you use
#include <iostream.h>
then you will get the problem.
If you use
#include <iostream>
(notice - without the .h)
then you will not get the problem you mentioned.
If you started a project requiring the #include "stdafx.h" line, put it first.
I've seen similar things happen when I was using the .c file extension with C++ code. Other than that, I'd have to agree with everyone about a buggy installation. Does it work if you try to compile the project with an earlier release of VS? Try VC++ Express 2008. Its free on msdn.
Such a silly solution in my case:
// Example a
#include <iostream>
#include "stdafx.h"
The above was odered as per example a, when I changed it to resemble example b below...
// Example b
#include "stdafx.h"
#include <iostream>
My code compiled like a charm. Try it, guaranteed to work.
The code below compiles and runs properly for me using gcc. Try copy/pasting this and see if it works.
#include <iostream>
using namespace std;
int bob (int a) { cout << "hey" << endl; return 0; };
int main () {
int a = 1;
bob(a);
return 0;
}
I have VS2010, Beta 1 and Beta 2 (one on my work machine and one at home), and I've used std plenty without issues. Try typing:
std::
And see if Intellisense gives you anything. If it gives you the usual stuff (abort, abs, acos, etc.), except for cout, well then, that is quite a puzzler. Definitely look into your C++ headers in that case.
Beyond that, I would just add to make sure you're running a regular, empty project (not CLR, where Intellisense is crippled), and that you've actually attempted to build the project at least once. As I mentioned in a comment, VS2010 parses files once you've added an include; it could be that something stuck the parser and it didn't "find" cout right away. (In which case, try restarting VS maybe?)
Take the code
#include <iostream>
using namespace std;
out of your .cpp file, create a header file and put this in the .h file. Then add
#include "whatever your header file is named.h"
at the top of your .cpp code. Then run it again.
I had the same issue when starting a ms c++ 2010 project from scratch - I removed all of the header files generated by ms and but used:
#include "stdafx.h"
#include <iostream>
using namespace std;
int main() {
cout << "hey" << endl;
return 0;
}
I had to include stdafx.h as it caused an error not having it in.
Try it, it will work. I checked it in Windows XP, Visual Studio 2010 Express.
#include "stdafx.h"
#include <iostream>
using namespace std;
void main( )
{
int i = 0;
cout << "Enter a number: ";
cin >> i;
}
before you begin this program get rid of all the code and do a simple hello world inside of main. Only include iostream and using namespace std;.
Little by little add to it to find your issue.
cout << "hi" << endl;
Are you sure it's compiling as C++? Check your file name (it should end in .cpp). Check your project settings.
There's simply nothing wrong with your program, and cout is in namespace std. Your installation of VS 2010 Beta 2 is defective, and I don't think it's just your installation.
I don't think VS 2010 is ready for C++ yet. The standard "Hello, World" program didn't work on Beta 1. I just tried creating a test Win32 console application, and the generated test.cpp file didn't have a main() function.
I've got a really, really bad feeling about VS 2010.
When you created your project, you did not set 'use precompiled headers' correctly. Change it in properties->C/C++->precompiled headers.
In Visual studio use all your header filer below "stdafx.h".
Just use printf!
Include stdio.h in your stdafx.h header file for printf.
Include the std library by inserting the following line at the top of your code:
using namespace std;
is normally stored in the C:\Program Files\Microsoft Visual Studio 8\VC\include folder. First check if it is still there. Then choose Tools + Options, Projects and Solutions, VC++ Directories, choose "Include files" in the "Show Directories for" combobox and double-check that $(VCInstallDir)include is on top of the list.
I ran across this error after just having installed vs 2010 and just trying to get a nearly identical program to work.
I've done vanilla C coding on unix-style boxes before, decided I'd play with this a bit myself.
The first program I tried was:
#include "stdafx.h"
int _tmain(int argc, _TCHAR* argv[])
{
cout << "Hello World!";
return 0;
}
The big thing to notice here... if you've EVER done any C coding,
int _tmain(int argc, _TCHAR* argv[])
Looks weird. it should be:
int main( int argc, char ** argv )
In my case I just changed the program to:
#include <iostream>
using namespace std;
int main()
{
cout << "Hello world from VS 2010!\n";
return 0;
}
And it worked fine.
Note: Use CTRL + F5 so that the console window sticks around so you can see the results.
I came here because I had the same problem, but when I did #include "stdafx.h" it said it did not find that file.
What did the trick for me was: #include <algorithm>.
I use Microsoft Visual Studio 2008.
These are the things that you can use then, incl. 'count': Link
Had this problem, when header files declared "using namespace std;", seems to be confusing for GNU compiler;
anyway is bad style!
Solution was providing std::cout ... in headers and moving "using namespace std" to the implementation file.
In VS2017, stdafx.h seems to be replaced by pch.h see this article,
so use:
#include "pch.h"
#include <iostream>
using namespace std;
int main() {
cout << "Enter 2 numbers:" << endl;
It was the compiler - I'm now using Eclipse Galileo and the program works like a wonder