Templates in C++
Templates are a powerful feature of C++ that allow programmers to write generic and reusable code. Using templates, the same code can work with different data types without rewriting it multiple times.
Templates are widely used in the Standard Template Library (STL).
What is a Template?
A template is a blueprint that allows functions or classes to operate with generic data types. The actual data type is specified when the function or class is used.
This helps avoid code duplication.
Types of Templates in C++
C++ supports two main types of templates:
- Function Templates
- Class Templates
1. Function Templates
Function templates allow functions to work with different data types.
Syntax of Function Template
template <typename T>
T add(T a, T b) {
return a + b;
}
Advantages of Function Templates
- Code reusability
- Type safety
- Cleaner code
- Reduced maintenance
2. Class Templates
Class templates allow classes to operate with generic data types.
Syntax of Class Template
template <class T>
class Sample {
T data;
public:
void set(T value) {
data = value;
}
};
Use Case of Class Templates
- Stack implementation
- Queue implementation
- Generic data structures
Why Templates are Important
- Eliminate repetitive code
- Improve program efficiency
- Support multiple data types
- Increase flexibility
Real-World Example
Example: Storage Class
- int data
- float data
- char data
Templates allow one class to handle all cases.
Templates vs Function Overloading
| Templates | Function Overloading |
|---|---|
| Generic code | Specific functions |
| One definition | Multiple definitions |
| Less code | More code |
Template Specialization
Allows defining a special version of a template for a specific data type.
Used when default behavior is not sufficient.
Limitations of Templates
- Complex error messages
- Increased compile time
- Code bloat
Applications of Templates
- Standard Template Library (STL)
- Generic algorithms
- Data structures
- Mathematical computations
Common Mistakes to Avoid
- Overusing templates
- Writing unreadable code
- Ignoring template constraints
Conclusion
Templates are a core feature of C++ that enable generic programming. They reduce code duplication and increase flexibility, making programs efficient and reusable. Mastering templates is essential for understanding advanced C++ concepts and STL.