Visual Studio C3861

C3861 is a compiler error in Visual Studio that indicates that a function or identifier is not defined in the current scope. This error occurs when the compiler cannot find a definition for a function or identifier that is used in the code.

To resolve this error, make sure that the function or identifier is defined in the current scope or included in the appropriate header file. If the function or identifier is defined in a separate source file, make sure that the source file is included in the project and that the appropriate header files are included in the source file. Additionally, check for any spelling errors or typos in the function or identifier name.

Here is an example of code that could produce the C3861 error:

#include <iostream>

int main()
{
  std::cout << "Hello, world!" << std::endl;
  printMessage(); // error C3861: 'printMessage': identifier not found
  return 0;
}

In this example, the code tries to call a function named `printMessage`, but the function is not defined in the current scope or included in the appropriate header file. To fix this error, a definition for the `printMessage` function needs to be added to the code or included in the appropriate header file.