Templates in C++
Hello people, today we are going to read about the templates
in C++. This is one of the recently added features of C++. It is a concept
which enables us to define generic classes and functions and thus provide
support for generic programming. Generic programming is an approach where
generic types are used as parameters in algorithms so that they work for a
variety of suitable data types and data structures.
A template can be used to create a family of classes or
functions. For example, a class template for an array class would enable us to
create arrays of various data types such as int array and float array.
Since a template is defined with a parameter that would be
replaced by a specified data type at the time of actual use of the class or
function, the templates are sometimes called parameterized classes or
functions.
The concept of templates can be used in two different ways :
·
Function Templates
·
Class Templates
Function
Templates
A function template operates similarly as the normally defined
functions does. But with a one major key difference, that in function templates
you can use parameters of different types but in normal functions we can use
only the already defined type of data types.
We can also use function overloading for using a particular
function with parameters different types of data types, but using functions
templates is a way much better approach.
Function
Templates Declaration
A function template declaration starts with a keyword template followed by templates parameters
inside <……> which is followed by function declaration.
In above example, T is the argument of template which accepts
different data types (int, floor) and typename is keyword.
We can also use class
keyword in place of typename.
When an argument is passed to “function()” compiler generates
a completely different version of the “function()” for the given data type.
Class
Templates
As function
templates we can also create templates for generic classes.
Sometimes,
we need a class implementation that is same of all classes, only the data types
used are different.
Normally,
you would need to create a different class for each type or create different
member variables and functions with a single class.
However, class
templates make it easy to reuse the same code for all data types.
Class
Templates Declaration
