Explore the power of C++ templates, from function and class basics to advanced features like instantiation and concepts, enhancing code flexibility, reusability, and abstraction without performance loss.

cpp17.tar.gz

C++17

C++20

Templates are one of the many powerful features of Modern C++ programming. And with each new C++ standard, they become more important. 

Templates provide an efficient way to make your code more flexible and reusable, this way you can avoid repeating code that would otherwise be identical except for different types. Templates also give you the ability to provide abstraction without a performance penalty.

However, templates can be difficult to apply, can be counterintuitive, and have tricky error messages.

This course gives you the necessary information to overcome these hurdles and dive into the advanced topics. You’ll visit the basics such as function and class templates, and then explore the details to templates such as instantiation and fold expressions. Our journey also includes techniques based on templates, the design, and future directions of templates such as concepts. Based on this exhaustive tour of templates, a basic understanding of C++ is sufficient to master this course.

Let’s get started!

Generic Programming Templates in C++

### The Type Class Eq (Haskell)

```haskell
class Eq a where
  (==) :: a -> a -> Bool
  (/=) :: a -> a -> Bool




```


### The Concept Equal (C++)

```c++
template <typename T>
concept bool Equal(){
  return requires(T a, T b){
    { a == b } -> bool;
    { a != b } -> bool;
  };
}
```

Let's have a closer look at Haskell's type class `Eq`. `Eq` requires from its instances, that

 *   they have equal `==` and unequal `/=` operation that returns a Bool.
 *  both take two arguments (`a -> a`) of the same type.

If you compare Haskell's type class with C++'s concept, you see the similarity. 

Of course, the instances are the concrete types such as `int`. 

In this lesson, we'll define the concepts Equal and Ord for C++.

Introduction

Basics

Details

Techniques

Design

Future

Conclusion

Define your Concepts: Equal and Ord

`Eq` versus `Equal`

The Type Class Eq (Haskell)

The Concept Equal (C++)

Define your Concepts: Equal and Ord

Eq versus Equal

The Type Class Eq (Haskell)

The Concept Equal (C++)

`Eq` versus `Equal`