error C2039: ‘string’ : is not a member of ‘std’, header file problem

You need to have

#include <string>

in the header file too.The forward declaration on it’s own doesn’t do enough.

Also strongly consider header guards for your header files to avoid possible future problems as your project grows. So at the top do something like:

#ifndef THE_FILE_NAME_H
#define THE_FILE_NAME_H

/* header goes in here */

#endif

This will prevent the header file from being #included multiple times, if you don’t have such a guard then you can have issues with multiple declarations.

Related Posts:

  1. Error “C++ requires a type specifier for all declarations whilst defining methods”
  2. Expression must have class type
  3. How do I include the string header?
  4. c++ “Incomplete type not allowed” error accessing class reference information (Circular dependency with forward declaration)
  5. Why is enum class preferred over plain enum?
  6. Why am I getting this redefinition of class error?
  7. Single class has a Class Redefinition Error
  8. C++ Linked List Node with class
  9. (->) arrow operator and (.) dot operator , class pointer
  10. Separating class code into a header and cpp file
  11. how to define -std=c++11 as default in g++
  12. Pointer to incomplete class type is not allowed
  13. Why am I getting this redefinition of class error?
  14. push_back vs emplace_back
  15. no default constructor exists for class
  16. C++ Fatal Error LNK1120: 1 unresolved externals
  17. Visual Studio debugger error: Unable to start program Specified file cannot be found
  18. Getting error “a nonstatic member reference must be relative to a specific object” while both member are in the same class
  19. What are the differences between struct and class in C++?
  20. error C2011: ” : ‘class’ type redefinition
  21. push_back vs emplace_back
  22. General way of solving Error: Stack around the variable ‘x’ was corrupted
  23. The compiler is complaining about my default parameters?
  24. Already defined in .obj – no double inclusions
  25. C++ Linked List Node with class
  26. Getting error: ISO C++ forbids declaration of with no type
  27. IntelliSense: the object has type qualifiers that are not compatible with the member function
  28. “used without template parameters”
  29. Error “system” is ambiguous?
  30. expected constructor, destructor, or type conversion before ‘(’ token
  31. C++ Class ‘undeclared identifier”
  32. c++ “Incomplete type not allowed” error accessing class reference information (Circular dependency with forward declaration)
  33. Base class undefined
  34. Warning: non-static data member initializers only available with -std=c++11 or -std=gnu++11?
  35. What is the meaning of a C++ Wrapper Class?
  36. Does C++11 have C#-style properties?
  37. G++ undefined reference to class::function
  38. Creating an instance of class
  39. Error “Unterminated conditional directive” in cross-referencing headers
  40. expected primary-expression before ‘]’ token
  41. What is the return type of sizeof operator?
  42. error C2065: ‘cout’ : undeclared identifier
  43. How to install Visual Studio Build Tools 2010 on Visual Studio 2015 Community?
  44. istream and ostream problem – C++
  45. Struct with template variables in C++
  46. error: no member function declared in class
  47. Here is some error with my .h file which show [Error] unterminated #ifndef when I include my class template in it
  48. Error: invalid use of member in static member function
  49. Is “delete this” allowed in C++?
  50. How to create a dynamic array of integers
  51. How do I build a graphical user interface in C++? [closed]
  52. How to dynamically allocate arrays in C++
  53. What does (~0L) mean?
  54. How to throw a C++ exception
  55. How to fix C++ error: expected unqualified-id
  56. How to track down a “double free or corruption” error
  57. Error: “expression must have integral or unscoped enum type” [duplicate]
  58. How to fix C++ error: expected unqualified-id
  59. Reading from file in c++ ifstream
  60. How do I iterate over the words of a string?
  61. C++ IDE for Macs
  62. C++ Error: No match for ‘operator=’
  63. How to fix ‘No match for operator[]’ error (c++)
  64. std::cin.getline( ) vs. std::cin
  65. Vector is not a Template?
  66. Displaying a vector of strings in C++
  67. ‘vector’ in namespace ‘std’ does not have a template type
  68. Floating Point Exception C++ Why and what is it?
  69. Issue with std::stol – ‘std::invalid_argument’ what(): stol
  70. Writing a LinkedList destructor?
  71. Is there ‘byte’ data type in C++?
  72. How to return a string from a C++ function?
  73. C++, random number w/ range of 1-6
  74. What does “missing template argument” mean?
  75. How do conversion operators work in C++?
  76. What is the difference between isdigit() and isnumber()?
  77. Convert char* to string C++
  78. C++ delete vector, objects, free memory
  79. Copy a file in a sane, safe and efficient way
  80. c++ convert string to hex
  81. LINK : fatal error LNK1561: entry point must be defined ERROR IN VC++
  82. Multiple OR or AND conditions in IF statement
  83. What does it mean double free detected in tcache 2 while using mpz?
  84. What is the C equivalent to the C++ cin statement?
  85. c++ Read from .csv file
  86. Check if C++ Array is Null
  87. Random not declared in scope
  88. Destructor for a doubly-linked list that points to its value
  89. cin.ignore(numeric_limits::max(), ‘\n’)
  90. LLVM Compiler 2.0: Warning with “using namespace std;”
  91. ERROR: Control may reach end of non-void function /
  92. Function stoi not declared
  93. What’s the difference between while(cin) and while(cin >> num)
  94. Too many arguments to function
  95. not declared in this scope’ when using strlen()
  96. Converting a Cubemap into Equirectangular Panorama
  97. Why is this vector iterator not incrementable?
  98. glibc detected : double free or corruption
  99. How to implement Java “Scanner” in C++?
  100. Get Current Time in mm/dd/yyyy in C++

Leave a Comment