Template in class

Similar to function templates, we can use class templates to create a single class to work with different data types. In the above declaration, T is the template argument which is a placeholder for the data type used, and class is a keyword. Inside the class body, a member variable var and a member function functionName are both of type T. Once we've declared and defined a class template, we can create its objects in other classes or functions such as the main function with the following syntax.

Notice that the variable num , the constructor argument n , and the function getNum are of type T , or have a return type T. That means that they can be of any type. This creates a class definition each for int and float , which are then used accordingly. It is compulsory to specify the type when declaring objects of class templates. Otherwise, the compiler will produce an error. Suppose we need to define a function outside of the class template.

Exactly as the OP asked. Yes, template member functions are perfectly legal and useful on numerous occasions. The only caveat is that template member functions cannot be virtual. Tobias Tobias 6, 3 3 gold badges 34 34 silver badges 62 62 bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name.

Email Required, but never shown. The Overflow Blog. Podcast Making Agile work for data science. Stack Gives Back The easiest way is to simply put all of your template class code in the header file in this case, put the contents of Array. In this way, when you include the header, all of the template code will be in one place. The upside of this solution is that it is simple.

This is our preferred solution unless the compile or link times start to become a problem. If you feel that putting the Array. That yields the same result as putting all the code in the header, but helps keep things a little more organized.

If you use the. This results in the contents of the. Excluding the. The setting will be somewhere in there. Other solutions involve including. Class declaration. Access specifiers. Virtual function. Default constructor. Copy constructor. Copy assignment. Class template. Function template. Template specialization. Parameters and arguments. Function templates. Class member templates. Template argument deduction. Explicit full specialization. Partial specialization.

Dependent names. Contents 1 Syntax 2 Explanation 3 Class template instantiation 3. The class name declared becomes a template name. Files that instantiated exported templates did not need to include their definitions: the declaration was sufficient. Implementations of export were rare and disagreed with each other on details.