error LNK2019: unresolved external symbol “” referenced in function

Most likely cause is that you’re not linking in the object created from Agent.cpp.

You should check to ensure that it’s part of the project and that you’re using the correct version, compiled with this current compiler as well (since you state you haven’t touched it in a while, it may be that the objects were built with an earlier compiler version, potentially making them incompatible – different name mangling methods, for example).

The first thing to try (once you’ve established all correct files are in the project) is a full clean-and-build.

On a few other points:

  1. The error is occurring in World::processMouse meaning that the source for GLView::processMouse is probably irrelevant.
  2. I find your mixing of printf and cout slightly … disturbing. You should probably avoid printf for serious C++ programming. It works, but it’s mostly intended for legacy C support.

Related Posts:

  1. Unresolved external symbol in object files
  2. Unresolved external symbol in object files
  3. What is an undefined reference/unresolved external symbol error and how do I fix it?
  4. What is an undefined reference/unresolved external symbol error and how do I fix it?
  5. How to use _CRT_SECURE_NO_WARNINGS
  6. Windows 7 exception code: 0xc0000409
  7. Difference between ‘strcpy’ and ‘strcpy_s’?
  8. VC++ fatal error LNK1168: cannot open filename.exe for writing
  9. Exception Error c0000005 in VC++
  10. Visual Studio debugger error: Unable to start program Specified file cannot be found
  11. Identifier is undefined
  12. VC++ fatal error LNK1168: cannot open filename.exe for writing
  13. LINK : fatal error LNK1561: entry point must be defined ERROR IN VC++
  14. LINK : fatal error LNK1561: entry point must be defined ERROR IN VC++
  15. Win32 Console Application
  16. https://stackoverflow.com/questions/3865946/error-generic-array-creation
  17. C++ Compiler Error C2280 “attempting to reference a deleted function” in Visual Studio 2013 and 2015
  18. error C2601: ‘main’ : local function definitions are illegall – MS VS 2013 Compiler
  19. cin.eof() functionality
  20. LINK : fatal error LNK1561: entry point must be defined ERROR IN VC++
  21. LPCSTR, LPCTSTR and LPTSTR
  22. error LNK2019: unresolved external symbol _WinMain@16 referenced in function ___tmainCRTStartup
  23. Download c++ in existing visual studio 2017
  24. module unsafe for SAFESEH image C++
  25. Unexpected end of file error
  26. Is “delete this” allowed in C++?
  27. What is a segmentation fault?
  28. How many spaces for tab character(\t)?
  29. How to create a dynamic array of integers
  30. How to create a dynamic array of integers
  31. Linker Error C++ “undefined reference ” [duplicate]
  32. Microsoft Visual C++ 14.0 is required (Unable to find vcvarsall.bat)
  33. How do I build a graphical user interface in C++? [closed]
  34. C++ convert from 1 char to string?
  35. How do I build a graphical user interface in C++? [closed]
  36. convert a char* to std::string
  37. system(“pause”); – Why is it wrong?
  38. Pause Console in C++ program
  39. system(“pause”); – Why is it wrong?
  40. Pause Console in C++ program
  41. How to implement 2D vector array?
  42. Why the switch statement cannot be applied on strings?
  43. What is the difference between g++ and gcc?
  44. How to use setprecision in C++
  45. How to dynamically allocate arrays in C++
  46. What does (~0L) mean?
  47. How to dynamically allocate arrays in C++
  48. What is the best way to use a HashMap in C++?
  49. What is the best way to use a HashMap in C++?
  50. What are the differences between a pointer variable and a reference variable in C++?
  51. Sleep for milliseconds
  52. How to convert string to char array in C++?
  53. How can I convert a std::string to int?
  54. Easiest way to convert int to string in C++
  55. What is the difference between float and double?
  56. Why is “using namespace std;” considered bad practice?
  57. What is the easiest way to initialize a std::vector with hardcoded elements?
  58. outputting ascii table in C++
  59. What is a lambda expression in C++11?
  60. Vector of Vectors to create matrix
  61. How to throw a C++ exception
  62. std::string to char*
  63. How to generate a random number in C++?
  64. pinpointing “conditional jump or move depends on uninitialized value(s)” valgrind message
  65. How do I find the length of an array?
  66. Sleep for milliseconds
  67. How to convert string to char array in C++?
  68. C++ — expected primary-expression before ‘ ‘
  69. Using getline() with file input in C++
  70. What is the effect of extern “C” in C++?
  71. C++ Cout & Cin & System “Ambiguous” [closed]
  72. ld: symbol(s) not found for architecture x86_64 error
  73. C++ string to double conversion
  74. Why are #ifndef and #define used in C++ header files?
  75. g++ ld: symbol(s) not found for architecture x86_64
  76. What exactly is the difference between “pass by reference” in C and in C++?
  77. How to throw a C++ exception
  78. Conversion from string to char – c++
  79. How to find out if an item is present in a std::vector?
  80. What is meant by Resource Acquisition is Initialization (RAII)?
  81. When to use extern “C” in simple words? [duplicate]
  82. What is `CString`?
  83. Floating point exception( core dump
  84. Initializing an array of objects
  85. Passing Arrays to Function in C++
  86. What does the explicit keyword mean?
  87. How do I print out the contents of a vector?
  88. Difference between != and =! with an example(in C++)
  89. Expression must have class type
  90. The static keyword and its various uses in C++
  91. Passing an array by reference
  92. Return array in a function
  93. What is the ‘override’ keyword in C++ used for? [duplicate]
  94. C++ equivalent of Java’s toString?
  95. How do sizeof(arr) / sizeof(arr[0]) work?
  96. Mutex example / tutorial? [closed]
  97. “std::bad_alloc”: am I using too much memory?
  98. Is there any built-in factorial function in c++?
  99. Making my own toString() method on c++ struct
  100. Struct Constructor in C++?

Leave a Comment