What are the differences between C++20 concepts and templates?

What are the differences between C++20 concepts and templates?

C++20 concepts are a way to specify constraints on template parameters, making templates easier to use and understand. Templates are a fundamental feature of C++ that allows for generic programming, but they can lead to complex error messages if constraints aren't clear.

Can you give me an example of how concepts improve template usage?

Sure! With concepts, you can define a template that only accepts types that meet certain criteria. For example, you can create a concept that requires a type to be an integral type, which simplifies the template's implementation and error handling.

How do I define a concept in C++20?

You define a concept using the concept keyword followed by a boolean expression that checks the properties of the type. For example: template<typename T> concept Integral = std::is_integral<T>::value;.

Are there any performance differences between using concepts and templates?

Generally, there are no significant performance differences. Concepts are resolved at compile time, just like templates, but they can lead to better-optimized code by providing clearer constraints.