I have recently attempted to switch my C++ project's target from an executable to a dynamic library (.dylib), and as soon as I rebuilt with the new target, I get a few errors saying that some defines and declarations in math.h are undeclared, such as M_PI and the sqrt() function.
The error message is as follows: error: use of undeclared identifier 'M_PI', and error: use of undeclared identifier 'sqrt'
This only occurs when I am building my project as a library, and I cannot figure out why it is doing this.
If anyone can help me out on this, it would be much appreciated!
Edit:
Also, if I try to change my include to #include <cmath>, I get more errors, such as: No member named 'signbit' in the global namespace.
Make sure #include <cmath> is at the top of the code, above int main(). I had the same problem. moving the #include <cmath> below <iostream> and above int main() solved the problem for me.
Related
I'm creating windows console app that has many pages (split in files). I'm facing a problem when executing the program and Visual Studio throws 'startpage' identifier not found error (startpage is the function and the file name is startpage.h)
I've tried using:
external int startpage(); and
int startpage();.
I've tried changing only the function name too (so the file and function don't use the same name).
I have no idea why this is happening. Other files with different functions are working. The file "startpage.h" uses two functions defined in other files, and those are not throwing any errors.
#include "include/startpage.h"
#include <iostream>
#include <conio.h>
#include "include/concol.h"
#include "pch.h"
#include <iostream>
using namespace std;
int main()
{
startpage();
}
```
Here is the error:
Error code: C3861: 'startpage' identifier not found
Move #include "pch.h" to the top. The compiler ignores everything above the inclusion of precompiled header. – Igor Tandetnik
This worked!
Thank you so much guys!
I just tried to compile my C++ code and an error appears when I try to do so.
The error appears on line 9
Here are the versions of the gcc and g++ and such
Any help would be appreciated.
Edit:
I am also including Movie.h:
And also Movie.cpp:
https://puu.sh/vb53G/9e9abd1832.png (I was not able to include more than 3 images due to restrictions)
Firstly, in your Movie.h file, you have not included the string header file correctly. It should be:
#include <string> // without the .h extension
error: 'string' does not name a type
Secondly, you have forgotten to add the closing parenthesis of the constructor function of class "Movie". I am assuming that you have added this now, after the edit
As for the marking done by your compiler, you may find the following StackOverflow post helpful:
StackOverflow Post: Unresolved inclusion iostream.
The link is for the Eclipse IDE, but you can find a similar solution for your own IDE (I cannot tell which one you have).
The line under the #include is just a warning (I'm not sure why).
However, the errors are from the "Movie" class:
1. add "using namespace std" on the top of this class.
2. close the parenthesis on the constructor of 'Movie'.
The error messages are fairly clear:
'string' does not name a type
That is, the compiler is unaware of the type string because either:
you have not #include <string> in Movie.h
or you have, but have not brought it into your namespace with a using namespace std;
although why not just refer to it as std::string?
You are missing
#include <string>
I'm having the same problem than this post.
Basically I am trying to compile a PIN tool that uses Python.h.
There are some types that are called the same for Windows.h and PIN.h and either of them declared a namespace for them so I'm getting error C2872: 'UINT32' : ambiguous symbol
The problem is that my PIN tool imports PIN.h and Python.h (which imports at the same time Windows.h) and both of them have same name types so the compiler doesn't know what type is each one and i'm getting the ambiguous symbols error
I cant use the solution:
namespace WINDOWS
{
#include <Windows.h>
}
or
namespace PIN
{
#include <PIN.h>
}
Because there are too many reference to them that need to be renamed and that would be a mess (PIN and Windows.h libraries uses UINT32 or CONTEXT a lot of times).
Is there any elegant way to fix this?
I have an extern code written in C in my C++ project in MS VS 2010. It comes with .h and .c files and I use include like this:
extern "C"{
#include "Extern\libname.h"
}
It worked nice. Then I read Google C++ style guide and removed all entries of
using namespace std;
replaced them with just
std::whatINeed
everywhere.
And the error showed up -
error C2065: 'FILE' : undeclared identifier
in the header of extern library. And then I move cursor to the word "FILE" in that code, there is
tydef _iobuf FILE
What should I add into my code to fix it? I don't want to change extern code because it can be updated and I will be forced to add my fixes on every update. Also, I am sure that there is a simple bug caused by me.
add
#include <cstdio>
above you include.
I am trying to get a get the boost library program_options working on a simple windows console library.
I have linked in the library
C:\Program Files\boost\boost_1_40\lib\libboost_program_options-vc90-s-1_40.lib
Included the header files
#include <boost/program_options.hpp>
#include <boost/program_options/config.hpp>
#include <boost/program_options/option.hpp>
#include <boost/program_options/detail/cmdline.hpp>
#include <boost/program_options/detail/parsers.hpp >
Defined _WIN32 (But I don't think it is required.)
And I still keep getting the
Error 1 error C3861: 'split_winmain': identifier not found
It should be so simple but I can't get it to work. Can anyone tell me what I need to do here.
Joseph Shanahan
That function is declared in the boost::program_options namespace. If all you do is use its name alone, the compiler doesn't know what you're talking about. You have a few options:
Use the fully qualified name when you call it:
boost::program_options::split_winmain(...);
Tell the compiler which function you mean:
using boost::program_options::split_winmain;
split_winmain(...);
Bring the entire namespace into the current scope:
using namespace boost::program_options;
split_winmain(...);
Make a namespace alias:
namespace po = boost::program_options;
po::split_winmain(...);
I prefer the last one.
Do not define the _WIN32 macro; the compiler will do that for you when it's appropriate.