Exploring C++ Templates

What is a template in C++?

• A template in C++ is a blueprint for creating functions or classes that can work with any data type.

• A template in C++ is a type of variable.

• A template in C++ is a specific instance of a class.

• A template in C++ is a function that only accepts integers.

How do function templates differ from class templates?

• Function templates require a specific return type, class templates do not.

• Class templates are for functions, while function templates are for classes.

• Function templates can only be used with integers.

• Function templates are for functions, class templates are for classes.

What is the purpose of the 'typename' keyword in templates?

• The 'typename' keyword is used to define a new template parameter.

• The 'typename' keyword indicates that a dependent name is a type in C++ templates.

• The 'typename' keyword specifies the return type of a function.

• The 'typename' keyword is used to create a new class in C++.

Can templates be used with non-type parameters? Give an example.

• template class Array { T data; U size; };

• Example: template class Array { T data[N]; };

• template class Array { int data[N]; };

• template class Array { T data; };

What is template specialization and when is it used?

• Template specialization is used to create generic functions for all data types.

• Template specialization is a method for optimizing code performance.

• Template specialization is a technique for debugging template errors.

• Template specialization is used to provide specific implementations of templates for particular data types.

Explain the concept of variadic templates in C++.

• Variadic templates allow only one template parameter in C++.

• Variadic templates are a feature exclusive to C programming.

• Variadic templates enable functions and classes to accept a variable number of template parameters in C++.

• Variadic templates are used to define fixed-size arrays in C++.

What are the advantages of using templates in C++?

• Slower compilation times

• Limited compatibility with data types

• Increased memory usage

• Code reusability, type safety, reduced code duplication, and improved performance.

How does the compiler handle template instantiation?

• Templates are instantiated at runtime only.

• The compiler ignores templates during compilation.

• The compiler creates a single version of the template regardless of parameters.

• The compiler generates specific versions of templates for each unique set of parameters during compilation.

What is the difference between a template and a macro in C++?

• Templates are only used for class definitions, while macros can be used for any code.

• Macros provide type safety, whereas templates do not.

• Templates are type-safe and allow for generic programming, while macros are simple text substitutions without type safety.

• Templates are evaluated at runtime, while macros are evaluated at compile time.

Provide an example of a simple template function that swaps two values.

• void swap(int &a, int &b) { int temp = a; a = b; b = temp; }

• template void swap(T &a, T &b) { T temp = a; a = b; b = temp; }

• template void exchange(T a, T b) { T temp = a; a = b; b = temp; }

• template void switchValues(T &a, T &b) { T temp = b; b = a; a = temp; }