Preview version of C# language uses incorrect constructor overloading for arrays #210
Description
Thanks for the great library!
First-class Span Types is currently under development. Recent changes, in particular Prefer converting T[] to ReadOnlySpan over Span in overload resolution, also affect the library.
See the following code for an example:
using System;
using System.Buffers;
class Program {
static void Main()
{
S(ArrayPool<char>.Shared.Rent(16));
S("abc");
}
static void S(Span<char> _) => Console.WriteLine("Span");
static void S(ReadOnlySpan<char> _) => Console.WriteLine("ReadOnlySpan");
}That is, by default, it's now easy to get into an invalid constructor overload when passing a buffer from an array. This is not something that will happen sometime in the future, to get problems you just need to enable the preview version of the language for .NET 9. For example, interesting issues: 1, 2
To resolve this issue, all you need to do now is add the OverloadResolutionPriority attribute
using System;
using System.Buffers;
using System.Runtime.CompilerServices;
class Program {
static void Main()
{
S(ArrayPool<char>.Shared.Rent(16));
S("abc");
}
[OverloadResolutionPriority(1)]
static void S(Span<char> _) => Console.WriteLine("Span");
static void S(ReadOnlySpan<char> _) => Console.WriteLine("ReadOnlySpan");
}It might be more correct to remove overloading with ReadOnlySpan<char>, for example by adding a static method to create a ValueStringBuilder from a given buffer. For example, .NET without it.