What Is A Class Template In C++?

C++ language is a very powerful programming language and is suitable for almost any software development task. One of the great features of modern C++ is templates. A template is a simple and a very powerful statement in C++ which defines the operations of a class or function and lets the user apply the same template on different types in those operations. In this post we will explain class templates in C++ which can be used by a professional C++ Compiler and IDE with C++ examples from this article .

What is a template in C++?

A template is a very powerful statement in C++ which simply defines the operations of a class, a function, an alias or a variable and lets the user apply the same template on different data types in those template operations. Templates are similar to macros in C++ except the compiler checks the types used before the template is expanded.

How does a template in C++ work?

Here is a function template that adds two a and b parameters in T type,

for example, if a and b are int variables, this template can be used as below

and in the next lines same template can be used for the x and y float variables as below too,

Templates can be parameterized by one or more template parameters. These parameters can be type template parameters, non-type template parameters, and template template parameters – templates as parameters are allowed, in templates!

What is a class template in C++?

A class template (also called a generic class or class generator) lets you define a pattern for class definitions. Consider the following example of a vector class, a one-dimensional array. Whether you have a vector of integers or any other type, the basic operations performed on the type are the same – insert, delete, index, and so on. With the element type treated as a type parameter to the class, the system will generate type-safe class definitions on the fly.

Here is the syntax for a class template,

As with function templates, an explicit template class specialization can be provided to override the automatic definition for a given type:

The symbol Vector must always be accompanied by a data type in angle brackets. It cannot appear alone, except in some cases in the original template definition.

How to declare a class template in C++?

When you create a class template you should start with template keyword then the parameters inside < >, for example

How to create objects from a class template in C++?

If you declared a class template, you could create objects from this template. You just need to type the class name with a data type and then the object name.

Here is the syntax to create a class template:

here is an example to create objects:

Is there a full example of a class template in C++?

Here is a full class template example

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