Custom String Classes

Yes, std::string_view can be used with custom string classes, but it requires the custom class to provide a compatible interface.

Specifically, the custom string class should offer methods to access the underlying data and size, similar to std::string.

Requirements

For std::string_view to work with a custom string class, the class should provide:

• A method to return a pointer to the underlying character data (e.g., data())
• A method to return the size of the string (e.g., size())

Here is an example of a custom string class that meets these requirements:

1#include <iostream>
2#include <string_view>
3
4class MyString {
5 public:
6  MyString(const char* str)
7    : data_{str} {}
8
9  const char* data() const {
10    return data_;
11  }
12
13  size_t size() const {
14    return std::strlen(data_);
15  }
16
17 private:
18  const char* data_;
19};
20
21int main() {
22  MyString myStr{"Hello, World!"};
23  std::string_view view{
24    myStr.data(), myStr.size()
25  };
26
27  std::cout << "String view: " << view;
28}

1String view: Hello, World!

Using with Custom Classes

The above example demonstrates a minimal custom string class compatible with std::string_view. Ensure your custom class methods align with what std::string_view expects: a pointer to character data and the length of the string.

Benefits

Using std::string_view with custom string classes:

• Avoids copying strings, enhancing performance
• Provides a unified interface for accessing string data
• Leverages the rich functionality of std::string_view

Considerations

• Lifetime Management: Ensure the custom string's data outlasts the std::string_view to prevent dangling references.
• Null-Termination: Custom string classes should handle null-terminated strings carefully if interfacing with C-style functions.
• Immutability: std::string_view treats the underlying string as immutable. To modify the string, convert it back to your custom class type.

Conclusion

Integrating std::string_view with custom string classes can be highly beneficial.

Ensure your class provides compatible methods, manage lifetimes carefully, and enjoy the performance benefits of using std::string_view in your applications.