Quick Answer

Improper calls to member functions

Understanding the Issue

This error occurs when trying to call non-static member functions without an object instance, or using member function pointers incorrectly.

The Problem

This code demonstrates the issue:

Cpp Error 
// Problem: Static call to instance method
class Test {
public:
    void work() {}
};
Test::work(); // Error

The Solution

Here's the corrected code:

Cpp Fixed 
// Solution 1: Create instance
Test t;
t.work();

// Solution 2: Make static
static void work() {} // Then Test::work() works

Key Takeaways

Non-static methods require an object instance.