# dll create github

// MathLibrary.cpp : Defines the exported functions for the DLL. #include "stdafx.h" // use pch.h in Visual Studio 2019 and later #include#include #include "MathLibrary.h" // DLL internal state variables: static unsigned long long previous_; // Previous value, if any static unsigned long long current_; // Current sequence value static unsigned index_; // Current seq. position // Initialize a Fibonacci relation sequence // such that F(0) = a, F(1) = b. // This function must be called before any other function. void fibonacci_init( const unsigned long long a, const unsigned long long b) { index_ = 0; current_ = a; previous_ = b; // see special case when initialized } // Produce the next value in the sequence. // Returns true on success, false on overflow. bool fibonacci_next() { // check to see if we'd overflow result or position if ((ULLONG_MAX - previous_ < current_) || (UINT_MAX == index_)) { return false; } // Special case when index == 0, just return b value if (index_ > 0) { // otherwise, calculate next sequence value previous_ += current_; } std::swap(current_, previous_); ++index_; return true; } // Get the current value in the sequence. unsigned long long fibonacci_current() { return current_; } // Get the current index position in the sequence. unsigned fibonacci_index() { return index_; }

**Here is what the above code is Doing:**

1. The first line of the code is a preprocessor directive. This tells the compiler to include the contents of the stdafx.h file in the current file.

2. The next line is a preprocessor directive that tells the compiler to include the contents of the MathLibrary.h file in the current file.

3. The next three lines are variable declarations. These variables are used to store the state of the Fibonacci sequence.

4. The next function is the fibonacci_init function. This function is used to initialize the Fibonacci sequence.

5. The next function is the fibonacci_next function. This function is used to calculate the next value in the Fibonacci sequence.

6. The next function is the fibonacci_current function. This function is used to get the current value in the Fibonacci sequence.

7. The next function is the fibonacci_index function. This function is used to get the current index position in the Fibonacci sequence.

The next step is to build the DLL. To do this, open the Developer Command Prompt for VS 2019 and navigate to the directory where you saved the MathLibrary.cpp file. Then, type the following command:

cl /LD MathLibrary.cpp

This command will build the DLL and create a file named MathLibrary.dll.

Now that you have a DLL, you can create a program that uses it. To do this, create a new file named MathClient.cpp and add the following code: