A generic API for string-like objects

[int19h]

.NET is missing a convenient way to define a method that can take something "string-like" with minimal overhead. Most existing APIs just take String, meaning that callers need to call ToString, often creating full copies that are then used only to look at a few characters at the beginning. Some types that are commonly affected by this are StringBuilder and Uri.

This could be solved by adopting a common interface like IString for all these types, which could offer the same operations that String does; and implementing that interface on all standard types that have string as a public representation of any valid value.

The closest existing equivalent is Java CharSequence.

[KrzysztofCwalina]

I am not a big fan of string abstraction (or in general abstractions for language primitives). Abstractions add complexity and performance overhead that often cannot be afforded int he very primitive types.

But I do agree that there is a problem with ToString allocations. Take a look at https:/dotnet/corefxlab/wiki/System.Text.Formatting for how we are exploring to fix that.

[AlexGhiondea]

I agree with @KrzysztofCwalina - I am not convinced we need the IString abstraction.

The allocations that StringBuilder incurs should be solved by the new StringFormatter class.

Feel free to reopen if you have other scenarios where this would be useful.