Add clarification for C++ template parameter and arguments

Author: methylDragon

C++/06 C++ - Templates.md

@@ -16,41 +16,21 @@ This time, we'll be going through C++ templates!!
 
 
 
-## Table Of Contents <a name="top"></a>
+## Table Of Contents
 
-1. [Introduction](#1)    
-2. [C++ Templates Reference](#2)    
-   2.1 [Template Concept](#2.1)    
-   2.2 [Function Templates](#2.2)    
-   2.3 [Class Templates](#2.3)    
-   2.4 [Template Variables](#2.4)    
-   2.5 [Multiple Arguments](#2.5)    
-   2.6 [Default Arguments](#2.6)    
-   2.7 [Some Notes](#2.7)    
-3. [Template Metaprogramming](#3)    
-   3.1 [Template Parameters vs Template Arguments](#3.1)    
-   3.2 [Template Specialisation](#3.2)    
-   3.3 [Partial Specialisation](#3.3)    
-   3.4 [Non-Type Template Arguments](#3.4)    
-   3.5 [Template Argument Deduction](#3.5)    
-   3.6 [SFINAE (Substitution Failure Is Not An Error)](#3.6)    
 
 
-
-
-## 1. Introduction <a name="1"></a>
+## Introduction
 
 So we spent the previous section talking about a couple of uses of the STL library. But have you ever wondered what templates are?
 
 >  **Templates** are powerful features of **C++** which allows you to write generic programs. In simple terms, you can create a single function or a class to work with different data types using **templates**. **Templates** are often used in larger codebase for the purpose of code reusability and flexibility of the programs.
 
 
 
-## 2. C++ Templates Reference <a name="2"></a>
-
-### 2.1 Template Concept <a name="2.1"></a>
-[go to top](#top)
+## C++ Templates Reference
 
+### Template Concept
 
 The idea of templates is a very powerful one. It allows you to wrap C++ with a type of 'metalanguage' that allows you to write generic functions that can deal with a multitude of data types.
 
@@ -62,9 +42,7 @@ The idea of templates is a very powerful one. It allows you to wrap C++ with a t
 
 
 
-### 2.2 Function Templates <a name="2.2"></a>
-[go to top](#top)
-
+### Function Templates
 
 Let's look at a simple example for defining function templates!
 
@@ -94,9 +72,7 @@ T maximise(T x, T y)
 
 
 
-### 2.3 Class Templates <a name="2.3"></a>
-[go to top](#top)
-
+### Class Templates
 
 You can template into classes too!
 
@@ -146,9 +122,7 @@ int main() {
 
 
 
-### 2.4 Template Variables <a name="2.4"></a>
-[go to top](#top)
-
+### Template Variables
 
 You can even declare variables as templates!
 
@@ -164,9 +138,7 @@ pi<long>; // So on and so forth
 
 
 
-### 2.5 Multiple Arguments <a name="2.5"></a>
-[go to top](#top)
-
+### Multiple Arguments
 
 You can pass multiple arguments to templates! Just add on more stuff.
 
@@ -181,9 +153,7 @@ T maximise(T x, U y)
 
 
 
-### 2.6 Default Arguments <a name="2.6"></a>
-[go to top](#top)
-
+### Default Arguments
 
 ```c++
 template <typename T, typename U = int> 
@@ -196,9 +166,7 @@ T maximise(T x, U y)
 
 
 
-### 2.7 Some Notes <a name="2.7"></a>
-[go to top](#top)
-
+### Some Notes
 
 > **What is the difference between function overloading and templates?**
 > Both function overloading and templates are examples of polymorphism feature of OOP. Function overloading is used when multiple functions do similar operations, templates are used when multiple functions do identical operations.
@@ -214,7 +182,7 @@ So the reason you have multiple static members is because the templates actually
 
 
 
-## 3. Template Metaprogramming <a name="3"></a>
+## Template Metaprogramming
 
 ![giphy](assets/giphy.gif)
 
@@ -226,9 +194,7 @@ But the main benefit of using templates to such a degree is greater generality o
 
 
 
-### 3.1 Template Parameters vs Template Arguments <a name="3.1"></a>
-[go to top](#top)
-
+### Template Parameters vs Template Arguments
 
 > Example: `template <PARAMETER_LIST> struct <ARGUMENT_LIST>`
 
@@ -241,12 +207,23 @@ void fun<int>(int a) // This second <> is known as the template argument list
 }
 ```
 
+Template parameters are used to first decide which template to even use.
 
+Then the arguments serve as a way to further declare explicitly the expected types of the arguments. (Which could use the template argument types.)
+
+```c++
+// Example
+template <typename T> 
+T maximise<T>(T x, T y) 
+{ 
+   return (x > y) ? x : y; // Return the maximum 
+} 
+```
 
-### 3.2 Template Specialisation <a name="3.2"></a>
-[go to top](#top)
 
 
+### Template Specialisation
+
 Suppose you have a generic function, but you realise that one particular possible input type can be treated in a far, far more efficient way.
 
 **Turns out you can write a special template function just for that type, so every other input type other than that type resolves the general template definition, but you create a specialised template just for that one input type!**
@@ -342,9 +319,7 @@ public:
 
 
 
-### 3.3 Partial Specialisation <a name="3.3"></a>
-[go to top](#top)
-
+### Partial Specialisation
 
 Partial specialisation works for structs and classes.
 
@@ -397,9 +372,7 @@ int main() {
 
 
 
-### 3.4 Non-Type Template Arguments <a name="3.4"></a>
-[go to top](#top)
-
+### Non-Type Template Arguments
 
 They're like another way to include arguments!
 
@@ -427,9 +400,7 @@ arrMin<int, 100>(arr1, n1);
 
 
 
-### 3.5 Template Argument Deduction <a name="3.5"></a>
-[go to top](#top)
-
+### Template Argument Deduction
 
 This diagram shows how the final template is resolved if there are specialisations or multiple declarations of templates involved. **Note again that only base templates are overloaded for function templates!** 
 
@@ -454,9 +425,7 @@ If there is generally an exact match for the template arguments after passing th
 
 
 
-### 3.6 SFINAE (Substitution Failure Is Not An Error) <a name="3.6"></a>
-[go to top](#top)
-
+### SFINAE (Substitution Failure Is Not An Error)
 
 ![giphy](assets/giphy-1562828095877.gif)