Error : aggregate ‘first one’ has incomplete type and cannot be defined

You can’t put the class declaration in the .cpp file. You have to put it in the .h file or else it’s not visible to the compiler. When main.cpp is compiled the type “first” is class first;. That’s not useful at all because this does not tell anything to the compiler (like what size first is or what operations are valid on this type). Move this chunk:

class first
{
public:
    int a,b,c;
    int sum(int a , int b);
};

from header1.cpp to header1.h and get rid of class first; in header1.h

Related Posts:

  1. undefined reference to WinMain@16 (codeblocks)
  2. Why am I getting “undefined reference to main”
  3. Cannot open output file, permission denied
  4. template argument 1 is invalid (Code::Blocks Win Vista) – i don’t use templates
  5. How to create a dynamic array of integers
  6. How to implement 2D vector array?
  7. What is the difference between g++ and gcc?
  8. What is the best way to use a HashMap in C++?
  9. What is the difference between float and double?
  10. How do I find the length of an array?
  11. C++ — expected primary-expression before ‘ ‘
  12. Using getline() with file input in C++
  13. g++ ld: symbol(s) not found for architecture x86_64
  14. ‘g++’ is not recognized as an internal or external command, operable program or batch file
  15. How do I convert a double into a string in C++?
  16. How to create timer events using C++ 11?
  17. How to concatenate two strings in C++?
  18. ‘g++’ is not recognized as an internal or external command, operable program or batch file
  19. Read file line by line using ifstream in C++
  20. Virtual/pure virtual explained
  21. error: redefinition of class
  22. Officially, what is typename for?
  23. How do I iterate over the words of a string?
  24. C++ Vector of pointers
  25. error: lvalue required as unary & operand
  26. Why doesn’t C++ have a garbage collector?
  27. How does ifstream’s eof() work?
  28. terminate called after throwing an instance of ‘std::invalid_argument’ what(): stoi
  29. How to find memory leak in a C++ code/project?
  30. Error: C++ requires a type specifier for all declarations
  31. invalid use of non-static member function
  32. Cannot open include file: ‘stdio.h’ – Visual Studio Community 2017 – C++ Error
  33. srand(time(0)) and random number generation
  34. How to convert integer to double implicitly?
  35. How do I tokenize a string in C++?
  36. Reverse Contents in Array
  37. Why would we call cin.clear() and cin.ignore() after reading input?
  38. Should I learn C before learning C++?
  39. cin >> “no operator matches these operands”
  40. C++ on mac : linker command failed with exit code 1 (use -v to see invocation)
  41. Correct way to use cin.fail()
  42. Destructor for a linked List
  43. Why use a new call with a C++ ‘vector’?
  44. Identifier is undefined
  45. What are the most widely used C++ vector/matrix math/linear algebra libraries, and their cost and benefit tradeoffs?
  46. Insert object at index of vector c++
  47. Read whole ASCII file into C++ std::string
  48. Reading getline from cin into a stringstream (C++)
  49. How to make an array with a dynamic size? General usage of dynamic arrays (maybe pointers too)?
  50. Delete 2D array C++
  51. class not declared in scope – even though .h was included
  52. Best C/C++ Network Library
  53. How to check that an element is in a std::set?
  54. Best way to extract a subvector from a vector?
  55. How do malloc() and free() work?
  56. Call to implicitly deleted copy constructor in LLVM
  57. C++ Linked List Node with class
  58. What is the use of intptr_t?
  59. why is string not declared in scope
  60. How does rhs work?
  61. error: expected unqualified-id before ‘.’ token //(struct)
  62. Base class undefined
  63. C++ – Assigning null to a std::string
  64. The program can’t start because libgcc_s_dw2-1.dll is missing
  65. C++ – Too Many Initializers for Arrays
  66. Reading string by char till end of line C/C++
  67. getline: identifier not found
  68. Colorizing text in the console with C++
  69. Show two digits after decimal point in c++
  70. error: invalid initialization of non-const reference of type ‘int&’ from an rvalue of type ‘int’
  71. gcc: undefined reference to
  72. C++ printing boolean, what is displayed?
  73. GCC -fPIC option
  74. initialize a vector to zeros C++/C++11
  75. “vector” was not declared in this scope
  76. Converting string to ASCII
  77. got “cannot appear in a constant-expression” when using template
  78. C++ ostream and ofstream conversions
  79. C++ discards qualifiers
  80. too many initializers for ‘int [0]’ c++
  81. function does not take 1 arguments c++
  82. overloaded function with no contextual type information
  83. How exactly do lookup tables work and how to implement them?
  84. Vector declaration “expected parameter declarator”
  85. C++ Destructors with Vectors, Pointers,
  86. error C2065: ‘cout’ : undeclared identifier
  87. How to get the MD5 hash of a file in C++?
  88. C++ Error: Expected a type specifier
  89. Where to declare/define class scope constants in C++?
  90. Friend methods error
  91. Does WPF Work with C++?
  92. Multiple inputs on one line
  93. Where can I find ‘winmm.lib’ (I’m using Visual Studio 2012)
  94. What is a `char*`?
  95. Does static constexpr variable inside a function make sense?
  96. “Incomplete type not allowed ” when creating std::ofstream objects
  97. Compiler error C4430: missing type specifier – int assumed [duplicate]
  98. ‘&’ : illegal operation on bound member function expression [duplicate]
  99. Multiple definitions of “Main”
  100. Getting the error floating point exception: 8

Leave a Comment

techhipbettruvabetnorabahisbahis forumuedueduedueduseduseduseduseduedusedus