C/C++ :: Templated Data Structure - Error LNK2019 / Unresolved External Symbol
Mar 23, 2015
I am working on building a set of templated data structures for my own learning and have run in to an error when instantiating my templated linked list. I receive the following error:
error LNK2019: unresolved external symbol "public: __thiscall LinkedList<int>::~LinkedList<int>(void)" (??1?$LinkedList@H@@QAE@XZ) referenced in function _main
--LinkedList.h--
#ifndef LINKEDLIST_H
#define LINKEDLIST_H
template<class T>
class LinkedList {
I am currently working on an Account login system and when I run the program I receive this error message:
error LNK2019: unresolved external symbol
If you want to see the full code of the source file just ask
const int NUM_OF_ACCOUNTS = 1; Account *account = new Account[NUM_OF_ACCOUNTS]; int AccountSearch(int number, string password); foundAccount = AccountSearch(aNumSearch, passSearch); int AccountSearch(int n, string p); { int x = 0;
When I try to compile a program from a C book I am following I am getting these errors, I have looked for ways to resolve it but I wasn't able to.
Errors:
Error3error LNK2001: unresolved external symbol _druk_instructiesC:UsersIvoDocumentsVisual Studio 2012ProjectsConsoleApplication2ConsoleApplication2Handspel.objConsoleApplication2 Error4error LNK2001: unresolved external symbol _speler_keuzeC:UsersIvoDocumentsVisual Studio 2012ProjectsConsoleApplication2ConsoleApplication2Handspel.objConsoleApplication2 Error5error LNK2001: unresolved external symbol _machine_keuzeC:UsersIvoDocumentsVisual Studio
I'm trying to create a public and static field in a class called ResourceManager. But when trying to access the field even from inside the class it wont work. I'm getting this error message:
Error 1 error LNK2001: unresolved external symbol "public: static int ResourceManager::num" (?num@ResourceManager@@2HA)
Here's my code: ResourceManager.h
Code:
class ResourceManager { public: static int num; static void loadContent();
I'm doing a homework assignment where I have to calculate monthly interest from a starting balance. I've pulled several sections of the code from various parts of the book. So my problem may be that I'm not combining them correctly.
I'm getting the following error: Error1error LNK2019: unresolved external symbol "public: __thiscall SavingsAccount::SavingsAccount(void)" (??0SavingsAccount@@QAE@XZ) referenced in function _main
The ios flags are new to me and that may be part of the problem. As soon as I can get a working program, I'm going to make the starting balance and interest rate user inputs. But I get seem to get past this error.
#include <iostream> #include "namespaces.h" namespace mycode { void foo() { std::cout << "foo() called in the mycode namespace" << std::endl; } }
When I try to run this code i keep getting these errors;
Error1error LNK2019: unresolved external symbol "void __cdecl mycode::foo(void)" (?foo@mycode@@YAXXZ) referenced in function _mainC:UsersHomeDesktopgameDevWin32Project1Win32Project1Source1.objWin32Project1
My code is rather short, but when I compile it, I get 1 error about an unresolved external symbol, it probably has something to do with the file processing. . .
Just a basic keylogger using SDL
Keylogger.h #ifndef KEYLOGGER_H #define KEYLOGGER_H #include <fstream> #include <SDL.h> using namespace std; class Keylogger{
[Code] .....
Errors
Error1error LNK2019: unresolved external symbol __imp___CrtDbgReportW referenced in function "public: char const & __thiscall std::_String_const_iterator<class std::_String_val<struct std::_Simple_types<char> > >::operator*(void)const " (??D?$_String_const_iterator@V?$_String_val@U?$_Simple_types@D@std@@@std@@@std@@QBEABDXZ)C:Usersaviedocumentsvisual studio 2013ProjectsPracticePracticeKeylogger.objPractice
So even though I have so many issues with linking libraries, I apparently became the go-to person for a fellow college friend of mine for a sql library. He's using the mysql connector/c++ and his team has had quite a few issues getting it set up. I've solved two out of three issues:
1st issue I solved was that they didn't know how to build boost, I just linked it and they were good to go.
2nd issue I solved was that they were missing libmysql.lib, I just installed the mysql server onto their computer and linked that up. 3rd issue is where I am now stumped at, as they get a compile error: LNK2001 unresolved external symbol: _get_driver_instance().
The project builds on Win32 platform, but not on x64.
Full error message: dllentry.obj : error LNK2001: unresolved external symbol "class CFactoryTemplate * g_Templates" (?g_Templates@@3PAVCFactoryTemplate@@A)
The dllentry.cpp (a DirectShow base class) compiles on both platforms. It contains the external declarations:
extern CFactoryTemplate g_Templates[]; extern int g_cTemplates; g_Templates[] is then used in two functions: __control_entrypoint(DllExport) STDAPI DllGetClassObject(__in REFCLSID rClsID, __in REFIID riid, __deref_out void **pv)
[Code]...
myClass.cpp contains the definitions for the two externals in dllentry.cpp, at top level, just after the includes:
CFactoryTemplate* g_Templates=0; int g_cTemplates=0;
myClass.cpp also compiles by itself, but the project does not build. I checked all the libraries in the project settings and all seems to be OK, the 64 bit versions are used.
What should I do to make the project build for x64 platform?
#include <stdio.h> #include <tchar.h> #include <iostream> #include <string> #include <fstream>// enable writing to and reading from files #include <cstdlib> #include <time.h> using namespace std; class Person {
[Code] .....
Error list:
Code:
Error 1 error LNK2019: unresolved external symbol "void __cdecl saveperson(void)" (?saveperson@@YAXXZ) referenced in function _main H:Cry_DevProgrammingC++Using_class_ in_ c++Using_class_ in_ c++Using_class_ in_ c++.obj Error 2 error LNK2019: unresolved external symbol "void __cdecl displayperson(void)" (?displayperson@@YAXXZ) referenced in function _main H:Cry_DevProgrammingC++Using_class_ in_ c++Using_class_ in_ c++Using_class_ in_ c++.obj Error 3 error LNK2019: unresolved external symbol "void __cdecl editperson(void)" (?editperson@@YAXXZ) referenced in function _main H:Cry_DevProgrammingC++Using_class_ in_ c++Using_class_ in_ c++Using_class_ in_ c++.obj Error 4 error LNK1120: 3 unresolved externals H:Cry_DevProgrammingC++Using_class_ in_ c++DebugUsing_class_ in_ c++.exe 1
I'm trying to implement this queue class, and I don't know why it won't compile. I wrote a main function in the main.cpp file and even commented out the calls to functions add and removed and still gave me the fatal error.
My program will not run because of error LNK2028 "unresolved token" and error LNK2019 "unresolved external signal" and I do not know why. My teacher says that I need to make the constructor and display functions display class variables in different formats, but I do not know what to do with that. Here are my 3 files:
Header take 2.h:
#pragma once #include <iostream> #include <string> using namespace std; class Heading { private: string company, report;
[Code] ....
Here are the errors: Error1error LNK2028: unresolved token (0A0003C9) "public: __thiscall Heading::Heading(void)" (??0Heading@@$$FQAE@XZ) referenced in function "int __cdecl main(void)" (?main@@$$HYAHXZ)c:UsersOwnerdocumentsvisual studio 2012ProjectsClassLibrary2ClassLibrary2Source1.objClassLibrary2
So I tried to make a tile map function to display my map as tiles. I keep getting unresolved external symbol errors, I've included the header file, and used every declaration in it, but to be completely honest this is mostly just a try to see if I could do it, and so far I'm failing. So if you can see why I'm getting the error.
template <typename T> struct avl_tree { T data; int balance; struct avl_tree <T> *Link[2]; static int (*comp)(T, T); };
In main, I have a function like so: int compare(int a, int b) { return ( a - b ); }
Now how do I assign the function pointer in my avl_tree class to the compare function?
I did this: int (avl_tree<int>::*comp)(int, int) = compare;
But I got the compiler error: Tree_Test.cc: In function ‘int main()’: Tree_Test.cc:27:42: error: cannot convert ‘int (*)(int, int)’ to ‘int (avl_tree<int>::*)(int, int)’ in initialization
I am trying to create a few subclasses which all use the base class constructor, according to my book this is all fine and dandy by using the "using Baseclass::Baseclass", this doesnt work for me.
class Monster { public: Monster(char[], char[], char[], int); //The constructor, and its implemented. etc.. };
[Code] ....
Yet, i recieve this error: error LNK2019: unresolved external symbol "public: __thiscall Human::Human(char * const,char * const,char * const,int)"
Why is this? Does doing it this way create const pointers somehow? The constructor works fine with Monster, i am using the same calls, just changed to create Human instead of Monster. All files are included where they should, monster and human are declared in the same header.
I would like to define a templated class while implementing default value on templated arguments. I don't know how to do that with string templated variables.
For exemple:
Code: template <class T> class A { public: A() { version = ???? } std::string_base<T> version; };
I don't want to pass the default value as parameter of the constructor. how I can do this?
Assignment: Design a class to store measurements. The class should have two data items, feet and inches, both integers. The class must make sure that the number of inches never gets below zero or above 11. If inches is outside that range, adjust feet accordingly. (Yes this means feet might be a negative number.)
Create a default constructor and one which receives one integer, a number of inches.
Overload the following operators: addition, subtraction, equality, inequality, incrementation (both pre and post) (should add one to inches), and output (in the form of: F’I”)
Code: #include <iostream> using namespace std; class measurements {
private: int inches; double feet;
[Code] ....
I am getting a LNK2019 error and an LNK1120 errors:
Error 1 error LNK2019: unresolved external symbol _main referenced in function ___tmainCRTStartup
I am debugging a library. I can step into the code however the watch window doesn't show the values of any variables. It will display a message in the value field:
Code: m_pParentCXX0017: Error: symbol "m_pParent" not found
Interestingly it does show values for local variables in that function but not member functions. Most of my data members are member function though that I want to debug. I am using VS2010.