I've installed Boost using vcpkg. Now I'm trying a "Hello World" with Boost:process. Suppose I start with Boost commented out everything works fine
#include <iostream>
//#include <boost/process.hpp>
//#include <boost/process/windows.hpp>
//namespace bp = boost::process;
int main(int argc, char * argv[])
{
int result = std::system("echo Hello");
}
Now if I uncomment Boost but don't use it i.e. I still call
std::system("echo Hello");
it compiles but throws two link errors
"__declspec(dllimport) class boost::system::error_category const & __cdecl boost::system::system_category(void)" (__imp_?system_category#system#boost##YAABVerror_category#12#XZ) referenced in function "void __cdecl boost::system::`dynamic initializer for 'native_ecat''(void)" (??__Enative_ecat#system#boost##YAXXZ)
"__declspec(dllimport) class boost::system::error_category const & __cdecl boost::system::generic_category(void)" (__imp_?generic_category#system#boost##YAABVerror_category#12#XZ) referenced in function "void __cdecl boost::system::`dynamic initializer for 'errno_ecat''(void)" (??__Eerrno_ecat#system#boost##YAXXZ)
I've tried adding Additional Library Dependencies for
C:\vcpkg-master\installed\x86-windows\lib
C:\vcpkg-master\packages\boost_x86-windows\debug\bin
C:\vcpkg-master\packages\boost_x86-windows\debug\lib
C:\vcpkg-master\packages\boost_x86-windows\lib
C:\vcpkg-master\packages\boost_x86-windows\bin
but none of those resolve the error.
Does anyone know where to find the correct link librries?
If I actually call Boost with
int result = bp::system("echo Hello");
there are 9 unresolved externals.
As far as I can see, it's an installer issue with VCPKG.
I did it manually, I added this directory to
$(SolutionDir)..\vcpkg\installed\x64-windows\lib
To
Project -> Properties-> Liker -> Additional Library Directories
and added this line to stdafx.h
#pragma comment(lib, "boost_system-vc140-mt-1_65_1.lib")
You need to link boost_system. How you achieve that in your setup is up to you. Usually on MSVC it's automatic.
See the relevant documentation which has several useful approaches with examples: http://www.boost.org/doc/libs/1_65_1/more/getting_started/windows.html#link-your-program-to-a-boost-library
Related
I am getting an error in Visual Studio when compiling my program.
Error LNK2019 unresolved external symbol "public: __cdecl
Grid::Grid(void)" (??0Grid##QEAA#XZ) referenced in function
main Grid C:\Users\Ryan\Desktop\Dev\Grid\Grid\main.obj 1
Error LNK2019 unresolved external symbol "public: __thiscall
Grid::~Grid(void)" (??1Grid##QAE#XZ) referenced in function
_main Grid C:\Users\Ryan\Desktop\Dev\Grid\Grid\main.obj 1
This project works fine at my university but not on my own computer and I am not sure what is wrong.
My main.cpp:
#include <iostream>
#include "Grid.h"
using namespace std;
int main(int args, char **argv)
{
Grid grid;
// grid.LoadGrid("Grid1.txt");
// grid.SaveGrid("OutGrid.txt");
system("pause");
}
And my header file:
#pragma once
class Grid
{
public:
Grid();
~Grid();
void LoadGrid(const char filename[]);
void SaveGrid(const char filename[]);
private:
int m_grid[9][9];
};
Any help at all is appreciated, thanks.
Issue resolved from advise given on [error LNK2019: unresolved external symbol "public: __thiscall : constructor issue
"First in the library project do rightclick->properties, then under the tab General, Configuration Type should be Static library (.lib)."
Thanks everyone for your answers.
As per my understanding your grid class constructor and destractor implementation are missing. You should check your .cpp file, implemention like this
Grid(){}
~ Grid(){}
I normally work in c# and am out of my wits for this one . I used Walkthrough: Creating and Using a Dynamic Link Library (C++) to create a Dynamic Link Library.
I have defined two methods as shown below
DeveloperConsoleManager.h
#pragma once
#include "atlstr.h"
#ifdef DEVCONSOLEMANAGER_EXPORTS
#define DEVCONSOLEMANAGER_API __declspec(dllexport)
#else
#define DEVCONSOLEMANAGER_API __declspec(dllimport)
#endif
namespace DeveloperConsoleManager
{
class DeveloperConsoleLogic
{
public:
// Returns a + b
static DEVCONSOLEMANAGER_API double Add(double a, double b);
static DEVCONSOLEMANAGER_API bool CheckforValidFile(CString fileName);
};
}
DeveloperConsoleManager.cpp
// DeveloperConsoleManager.cpp : Defines the exported functions for the DLL application.
//
#include "stdafx.h"
#include "DeveloperConsoleManager.h"
namespace DeveloperConsoleManager
{
double DeveloperConsoleLogic::Add(double a, double b)
{
return a + b;
}
bool DeveloperConsoleLogic :: CheckforValidFile(CString fileName)
{
return false;
}
}
I use these methods in a .cpp file in a different project (type: Application (.exe)). When I Build the solution, there are following linker errors
Warning 1 warning C4273: 'DeveloperConsoleManager::DeveloperConsoleLogic::Add' : inconsistent dll linkage e:\md_69\developerconsolemanager\developerconsolemanager.cpp 10
Warning 2 warning C4273: 'DeveloperConsoleManager::DeveloperConsoleLogic::CheckforValidFile' : inconsistent dll linkage e:\md_69\developerconsolemanager\developerconsolemanager.cpp 16
Error 3 error LNK2028: unresolved token (0A0004F1) "public: static bool __cdecl DeveloperConsoleManager::DeveloperConsoleLogic::CheckforValidFile(class ATL::CStringT > >)" (?CheckforValidFile#DeveloperConsoleLogic#DeveloperConsoleManager##$$FSA_NV?$CStringT#_WV?$StrTraitMFC_DLL#_WV?$ChTraitsCRT#_W#ATL#####ATL###Z) referenced in function "public: void __thiscall CSaSsiConsoleUi::UploadSsiCheck(void)" (?UploadSsiCheck#CSaSsiConsoleUi##$$FQAEXXZ) E:\MD_69\DeveloperConsoleUI\SaSsiConsoleUI.obj
Error 4 error LNK2019: unresolved external symbol "public: static bool __cdecl DeveloperConsoleManager::DeveloperConsoleLogic::CheckforValidFile(class ATL::CStringT > >)" (?CheckforValidFile#DeveloperConsoleLogic#DeveloperConsoleManager##$$FSA_NV?$CStringT#_WV?$StrTraitMFC_DLL#_WV?$ChTraitsCRT#_W#ATL#####ATL###Z) referenced in function "public: void __thiscall CSaSsiConsoleUi::UploadSsiCheck(void)" (?UploadSsiCheck#CSaSsiConsoleUi##$$FQAEXXZ) E:\MD_69\DeveloperConsoleUI\SaSsiConsoleUI.obj
Error 5 error LNK1120: 2 unresolved externals E:\MD_69\Debug\DeveloperConsoleUi.exe
There is no linker error for the "Add" method.
I have already included "DeveloperConsoleManager.lib" in Linker -> Input -> Additional Dependencies. Please help me find out what exactly am I doing wrong.
I would be glad to add any additional information needed.
Thanks to #Igor Tandetnik and the awesome thing that is internet, I figured it out. I am adding it as an answer so that some one else might benefit.
The problem was with CString. The project in which the function was defined was a dynamic link library (dll) and the call was being made from an MFC application. Now, the issue was that, MFC uses for CString while the non-MFC dll uses .
CString in is defined as:
typedef ATL::CStringT< TCHAR, StrTraitMFC_DLL< TCHAR > > CString;
while in is defined as:
typedef CStringT< TCHAR, StrTraitATL< TCHAR > > CString;
This, as you can clearly see is different. The workaround I used was using CAtlString instead of CString . However, please feel free to suggest any better way if you come across.
I have the code presented later using Xerces-c, which can be built as a static or dynamic library. Failing to include of course results in a compiler error, however when I add #include <xercesc/util/PlatformUtils.hpp> visual studio 2012 gives me a linker errors saying:
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: static void __cdecl xercesc_3_1::XMLPlatformUtils::Initialize(char const * const,char const * const,class xercesc_3_1::PanicHandler * const,class xercesc_3_1::MemoryManager * const)" (__imp_?Initialize#XMLPlatformUtils#xercesc_3_1##SAXQBD0QAVPanicHandler#2#QAVMemoryManager#2##Z) referenced in function _main
1>main.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: static void __cdecl xercesc_3_1::XMLPlatformUtils::Terminate(void)" (__imp_?Terminate#XMLPlatformUtils#xercesc_3_1##SAXXZ) referenced in function __catch$_main$0
1>main.obj : error LNK2001: unresolved external symbol "__declspec(dllimport) public: static char const * const xercesc_3_1::XMLUni::fgXercescDefaultLocale" (__imp_?fgXercescDefaultLocale#XMLUni#xercesc_3_1##2QBDB)
Based on the dllimport part of the error it seems that it's failing to find a dll. This is confirmed by that when I build Xerces-c as a dynamic library and link to it the error goes away. However if I build Xerces-c as a static library and link to it the same error remains. So my question is why am I getting an error asking for a dll when I'm including and linking to a static library?
using namespace xercesc;
int main(int argc, char* argv[])
{
std::ifstream inputFile(argv[1]);
char c = inputFile.get();
while (inputFile.good()) {
std::cout << c;
c = inputFile.get();
}
try {
XMLPlatformUtils::Initialize();
}
catch (const XMLException& toCatch) {
// Do your failure processing here
return 1;
}
// Do your actual work with Xerces-C++ here.
//XercesDOMParser parser;
//parser.useScanner(XMLUni::fgDGXMLScanner);
XMLPlatformUtils::Terminate();
// Other terminations and cleanup.
return 0;
}
You need to compile your application with XERCES_STATIC_LIBRARY preprocessor macro to disable DLL import/export for Xerces library.
Also check that you link against static version of .lib files.
I'm getting these error messages
2>main.obj : error LNK2019: unresolved external symbol "public: __thiscall CEngine::CEngine(void)" (??0CEngine##QAE#XZ) referenced in function _WinMain#16
2>main.obj : error LNK2019: unresolved external symbol "public: void __thiscall CEngine::SetWindowSize(int,int,char const *,int)" (?SetWindowSize#CEngine##QAEXHHPBDH#Z) referenced in function _WinMain#16
2>main.obj : error LNK2019: unresolved external symbol "public: void __thiscall CEngine::Begin(void)" (?Begin#CEngine##QAEXXZ) referenced in function _WinMain#16
2>main.obj : error LNK2019: unresolved external symbol "public: int __thiscall CEngine::GetDisplayWidth(void)" (?GetDisplayWidth#CEngine##QAEHXZ) referenced in function _WinMain#16
2>main.obj : error LNK2019: unresolved external symbol "public: int __thiscall CEngine::GetDisplayHeight(void)" (?GetDisplayHeight#CEngine##QAEHXZ) referenced in function _WinMain#16
2>C:\Users\ethan\Desktop\C++ Projects\delveenginetest\Debug\delveenginetest.exe : fatal error LNK1120: 5 unresolved externals
This is my solution:
Solution 'delveenginetest' (2 projects)
DelveEngine
Include
delve.h
Engine.h
SetupSDL.h
stdafx.h
Engine.cpp
Main.cpp
SetupSDL.cpp
This is the code for Engine.h
#pragma once
#include "SetupSDL.h"
class CEngine
{
public:
CEngine(void);
~CEngine(void);
void SetWindowSize(int winW, int winH, const char* GameName, int windowMode);
void Begin(void);
int GetDisplayWidth(void);
int GetDisplayHeight(void);
private:
int deskW;
int deskH;
bool playing;
CSetupSDL* sdl_setup;
};
Code for Engine.cpp
#include "Include/stdafx.h"
#include "Include/Engine.h"
CEngine::CEngine(void)
{
playing = true;
deskW = GetSystemMetrics(SM_CXSCREEN);
deskH = GetSystemMetrics(SM_CYSCREEN);
}
CEngine::~CEngine(void)
{
}
void CEngine::SetWindowSize(int winW, int winH, const char* GameName, int windowMode)
{
// set up SDL for use
sdl_setup = new CSetupSDL(winW, winH, GameName, windowMode);
}
void CEngine::Begin(void)
{
while (playing && sdl_setup->GetMainEvent()->type != SDL_QUIT)
{
sdl_setup->Begin();
sdl_setup->End();
}
playing = false;
}
int CEngine::GetDisplayWidth(void){ return deskW; }
int CEngine::GetDisplayHeight(void){ return deskH; }
The DelveEngine project builds successfully, whereas the delveenginetest project fails.
What's wrong? I've looked everywhere for a reason, can't find one that suits me.
Despite the fact you're not providing all the sufficient information for a correct diagnosis of your problems, I'll try to share what I could imagine that might be the reasons for the linker errors:
I suppose the project delveenginetest you mention is meant to set up unit tests for the classes from the DelveEngine project.
Since you have a Main.cpp in your DelveEngine project, I'd guess it's simply build as an executable (successfully).
Your delveenginetest needs to link to the classes provided from the DelveEngine project, but that's actually not possible, since the .exe from DelveEngine can't be used for linking, you'll need a library to import it to another executable (the unit testing framework).
I'd recommend to separate out your classes/source files from DelveEngine project to make up a static or shared library, that can be linked from an application and the test framework simultaneously from within a single VS solution:
Solution 'DelveEngine' (3 projects)
DelveEngineLib (project [.lib/.dll])
Include
delve.h
Engine.h
SetupSDL.h
Engine.cpp
SetupSDL.cpp
DelveEngine (project [.exe])
Main.cpp
delveenginetest (project [.exe])
Main.cpp (TestFramework main definition)
Since I'm not very versed with it I don't know actually, if VS 2013 supports to setup projects consuming virtual resources (think of links to sources in the actual build environment), but this could be an alternative how to setup application and unit tests without need of an extra library.
I need to use bind and function in my program.But unfortunately vs2010 can't link my program.
I used following example from boost::bind documentation
#include <boost\bind.hpp>
#include <boost\function.hpp>
#include <functional>
class button
{
public:
boost::function<void()> onClick;
};
class player
{
public:
void play();
void stop();
};
button playButton, stopButton;player thePlayer;
void connect()
{
playButton.onClick = boost::bind(&player::play, &thePlayer);
stopButton.onClick = boost::bind(&player::stop, &thePlayer);
}
void main(int argc, char* argv[])
{
connect();
}
Error 1 error LNK2019: unresolved external symbol "public: void __thiscall player::stop(void)" (?stop#player##QAEXXZ) referenced in function "void __cdecl connect(void)" (?connect##YAXXZ)
i have tried the newest 32 and 64 verion of BoostPro and followed this tutorial http://www.youtube.com/watch?v=5AmwIwedTCM.All but vs still produces same error...
VS2010 project setting include/lib path
https://dl.dropbox.com/u/47585151/vs.png
however when I turned on
Linker->General->ShowProgress ->For Libraries Searched (/VERBOSE:Lib)
i noticed that VS is searching only for these libraries which are defined in
Linker->Input->Additional Dependencies
http://pastebin.com/BCpEt8Zq
is it possible to check which .lib boost need for boost::bind and boost::function under vs2010?
This problem has nothing to do with any boost library (both are header-only). Try to simply call start and stop from within connect and you should get the same error. Read it carefully, it tells you what is missing.