Templates
Templates:
Templates are an important feature in C++ that allows you to create generic code that works with different data types without duplicating the code for each type. They provide a mechanism for defining a blueprint or pattern for creating classes or functions that can be used with various data types.
There are two main types of templates in C++:
- Function Templates: Function templates allow you to define a generic function that can operate on different data types. You use placeholders called type parameters, represented by the ‘typename’ keyword or ‘class’ keyword, to specify the generic types.
template <typename T>
T add(T a, T b) {
return a + b;
}
int result1 = add(2, 3);
double result2 = add(2.5, 3.7);
In this illustration, the ‘add’ function template can be used with any data type that supports the ‘+’ operator.
- Class Templates: Class templates allow you to create generic classes that can work with different data types. Similar to function templates, you use type parameters inside angle brackets(‘<>’) to define the general types.
template <typename T>
class myContainer {
private:
T data;
public:
myContainer(T val): data(val) {}
T getValue() { return data; }
};
myContainer<int> container1(42);
myContainer<double> container2(3.14);
In this illustration, the ‘MyContainer’ class template allows you to create instances of the container with different datatypes.
Templates provide a way to achieve compile-time polymorphism, where the code is generated for specific data types during compilation. This makes template code highly efficient, as there’s no runtime overhead for genericity.
Templates are extensively used in the C++ Standard Library (STL) to provide generic containers, algorithms, and other components. They’re a key feature of modern C++ programming and are widely used in generic and high-performance code.
When using templates, it’s essential to consider potential code bloat, as the compiler will generate separate code for each combination of types used with the template. Still, using templates judiciously can lead to clean, maintainable, and efficient code that works seamlessly with various data types.
