Question

how does function overloading implement polymorphism

Answer 1

$\huge\mathfrak\red{Answer:}$

In C++ polymorphism is mainly divided into two types:

A) Compile time polymorphism

☑️ Function Overloading
☑️ Operator Overloading

B) Runtime polymorphism

☑️ Function overriding

As you can see Function Overloading is a sub-part of polymorphism thus if you are using it in your code you are unintentionally implementing polymorphism.