When working with strings, temporary objects are created all the time, even if you might not be really aware of it. Many times the temporary objects are irrelevant and only serve the purpose of copying data from one place to another (for example, from a function to its caller). This represents a performance issue because they require memory allocation and data copying, which is desirable to be avoided. For this purpose, the C++17 standard provides a new string class template called std::basic_string_view that represents a non-owning constant reference to a string (that is, a sequence of characters). In this recipe, you will learn when and how you should use this class.