Indirection requires pointer operand ошибка

I have the following functions, an initializeHeap function which takes in no arguments and outputs a Heap struct which I have defined. And an insertNode function which takes in a pointer to a heap struct and the number to be added to the heap. I call them in the main function as such:

h = initializeHeap();
Heap *p = *h;
insertNode(p,5);
insertNode(p,7);
insertNode(p,3);
insertNode(p,2);

I get this error when trying to do this:

error: indirection requires pointer operand

Any ideas? I can post more code if needed.

The struct Heap and function initializeHeap() are as follows:

typedef struct node{
    int data;
}Node;

typedef struct heap{
    int size;
    Node *dataArray;
}Heap;

Heap initializeHeap(){
    Heap heap;
    heap.size = 0;
    return heap;
}

The Indirection requires pointer operand error message is shown on the screen when the programmer has created a pointer to a variable by using *my_var instead of &my_var.

This article will provide detailed knowledge of this error and ways to solve it. First, let’s start with the reasons that cause this issue and find the best solutions.

The Indirection requires pointer operand error message occurs while programming because the compiler interpreted the indirect pointer operand. Some of the other reasons include syntax errors or compiling errors along with cannot take the address of an rvalue of type ‘byte’.

Other common reasons behind this situation involve:

• Using the wrong function
• Compiling error
• Wrong usage of the Buffer function
• Dereferencing the wrong array value

– Error in Syntax

Syntax errors are common while typing large programs. Syntax errors can include writing the wrong functions or using operations that create an undefined behavior. If the programmer is taking the address of a temporary object of type (any), and it is not defined, then during execution, an error will occur.

Moreover, if the programmer wants to create a pointer to their variable by using *my_var instead of &my_var, a syntax error will occur along with the pointer operand error message.

– Cannot Take the Address of an Rvalue of Type ‘Byte’

When the program cannot take the address of an rvalue of type ‘byte’, it shows a pointer error. It occurs when the conditional expression does not produce an lvalue. Following is an example for better understanding:

For Example:

– Using the Wrong Function

When a wrong function is used, just like a syntax error, it also shows an operand error in the program. In the below example, the atoi function returns an int, not int *.

Thus, there is no need to dereference the return value again. The compiler will show an error message if the programmer tries to dereference int. Here’s an example:

For example:

The error in here is “virtualAddress = *atoi(argv[2]);”.

– Compiling Error

When the compiler interprets the program as an indirect operation of a pointer, it means the compiler is an incompatible pointer to integer conversion, and so, the error occurs during execution.

In other words, if the compiler and pointer are incompatible, a pointer error will occur. Let’s explain this using an example.

Program Example:

Explanation:

In this example, the programmer has used owned operators of a pointer to a variable of integer type. Thus, the compiler interprets this as an indirect operation of a pointer.

Moreover, the function (long long * FindLength) declares a pointer to an integer of type long long, but since a compiling error occurred, the program will instead show an error message.

– Wrong Usage of the Buffer Function

Understanding the buffer function is important because the wrong usage of it can cause errors such as pointer issues in the program. Some programmers confuse between buffer and &buffer[0].

The programmer should use the buffer as an argument instead of &buffer[0]. Passing an array has the same procedure as passing a pointer to its first element or passing pointers to functions.

In the example below, the programmer has used the wrong buffer function in their array. The &buffer[0] causes a pointer operand error message to occur.

For example:

– Dereferencing the Wrong Array Value

When the programmer uses arr[n] within the function, it gives them the nth value in that array instead of giving a pointer. Therefore, if the user is trying to dereference that value (*arr[n]), it will not work unless they use an array of pointers with it.

How To Resolve the Indirection Requires Pointer Operand Error?

To resolve the Indirection requires pointer operand error message, the programmer has to pass their pointers from the functions or use correct, defined, and direct pointers and commands. Furthermore, this error can be fixed by solving the cannot take the address of an Rvalue of a type byte error.

Let’s see all the possible reasons that can solve this error. They are explained below in detail.

– Correct the Syntax Errors

Using the correct functions will eliminate syntax errors and get rid of error messages related to pointers. There are various software that help in detecting these errors and help the user to correct them.

Let’s take an example: the programmer is dereferencing a long program and needs it in an unsigned long int. Then instead of using “atoi” in “virtualAddress = *atoi(argv[1]);”, they should use the strtoul function. Here’s an example:

Program:

– Use Vector of Pointers C++ To Resolve the Error

When the programmer uses a vector of pointers c++ to resolve the error, they have to be careful with the pointers and operands. With the help of this function, the programmer can avoid pointer errors. Vector is used as an alternative to some pointers. Here’s an example;

For example:

The output:

As you can see, the same list of alphabets is displayed twice. To elaborate, the first statement in the main() function creates six characters with their identifiers or pointers. Whereas the second statement represents these characters with their memory addresses, resulting in a vector of pointers to chars.

– Solving (Cannot Take the Address of an Rvalue of Type ‘Byte’) Error

When the rvalue of byte type is not addressed, the (cannot take the address of an rvalue of type ‘byte’) error message occurs. Due to this error, a pointer error also arises. Therefore, the programmer must use the correct commands to remove this error.

Let’s see the correct commands from the example above.

Program

– Pass Pointer to Function C++: Compilation

As mentioned above, the user cannot apply the owned operators of a pointer to a variable of integer type. If they do that, the compiler will show an error because it will interpret the program as an indirect pointer operation.

Therefore, to remove this error, the programmer has to correct the syntax error and pass pointer to function C++. This means the pointer has to pass from the function for the compiler to interpret it correctly. However, this is suitable if the user is using C++ language. Let’s take an example.

Wrong program:

Conclusion

After reading this article completely, the reader will have maximum knowledge about this error and they will be able to resolve it using the different methods shown in this article. Some important points to keep in mind are:

• The pointer should define the operator. Otherwise, the error will occur.
• No usage of pointers can cause the same error to occur.
• While creating the pointers that will support the variables in the program, make sure to use the right functions.

The reader can now proceed to resolve similar programming errors by the guidance provided in this article. Thank you for reading!

Reference

• https://cs50.stackexchange.com/questions/30016/pset1-error-indirection-requires-pointer-operand
• https://stackoverflow.com/questions/38237355/error-indirection-requires-pointer-operand-int-invalid
• https://www.reddit.com/r/cs50/comments/4c7gn4/passing_pointers_to_functions_error_indirection/
• https://github.com/vlang/v/issues/3336
• https://linuxhint.com/cpp-vector-pointers-examples/#2

If you’re a developer, you may have come across the error message «Indirection requires pointer operand» when trying to compile your code. This error message is usually caused by an invalid ‘int’ type, which means that the compiler is expecting a pointer instead of an integer.

In this guide, we’ll provide tips and solutions for fixing the ‘Indirection Requires Pointer Operand’ error in your code.

Understanding the ‘Indirection Requires Pointer Operand’ Error

Before we dive into the solutions, let’s take a closer look at what the error message means.

In C and C++, the * operator is used for indirection, which means it accesses the value stored at the address pointed to by a pointer variable. For example, if you have a pointer variable ptr that points to an integer variable num, you can access the value of num using the * operator like this:

int num = 10;
int* ptr = #
int value = *ptr; // value is now 10

However, if you try to use the * operator on a non-pointer variable like an integer, you’ll get the ‘Indirection Requires Pointer Operand’ error. For example:

int num = 10;
int value = *num; // error: indirection requires pointer operand ('int' invalid)

This error message means that the compiler is expecting a pointer instead of an integer.

Solutions for the ‘Indirection Requires Pointer Operand’ Error

There are several ways to fix the ‘Indirection Requires Pointer Operand’ error, depending on the root cause of the problem.

Solution 1: Use a Pointer Variable

The simplest solution is to use a pointer variable instead of a non-pointer variable. For example:

int num = 10;
int* ptr = #
int value = *ptr; // value is now 10

Solution 2: Cast the Integer to a Pointer

If you need to use an integer variable as a pointer, you can cast it to a pointer type like this:

int num = 10;
int* ptr = (int*)num;
int value = *ptr; // value is now 10

Note that this solution is not recommended, as it can lead to undefined behavior if the integer value is not a valid memory address.

Solution 3: Use the Address-of Operator

You can also use the address-of operator (&) to get the memory address of an integer variable and assign it to a pointer variable like this:

int num = 10;
int* ptr = #
int value = *ptr; // value is now 10

This solution is similar to Solution 1 but may be useful in certain situations where you don’t have a pointer variable available.

FAQ

Q1: What causes the ‘Indirection Requires Pointer Operand’ error?

A: The error is caused by trying to use the * operator on a non-pointer variable like an integer.

Q2: Can I use a cast to fix the error?

A: Yes, you can cast the integer to a pointer type, but this is not recommended as it can lead to undefined behavior.

Q3: How can I avoid the error in the first place?

A: Make sure to use pointer variables when using the * operator for indirection.

Q4: Is the error specific to C and C++?

A: Yes, the error message is specific to C and C++.

Q5: Can I use the address-of operator to fix the error?

A: Yes, you can use the address-of operator to get the memory address of an integer variable and assign it to a pointer variable.

• Pointer Basics in C and C++
• Common C++ Compiler Errors and How to Fix Them
• Casting in C and C++
• The Address-of Operator in C and C++

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We hope this guide has been helpful in fixing the ‘Indirection Requires Pointer Operand’ error in your code. If you have any questions or suggestions on how to improve the guide, please let us know in the comments below.