Add StringBuilder Span-based APIs #22853
Description
Separated out of https://github.com/dotnet/corefx/issues/21281 for tracking purposes.
- Implement in System.Private.CoreLib in coreclr ("shared" with corert)
- Expose from System.Runtime contract in corefx
- Add tests to System.Runtime tests in corefx
namespace System.Text
{
public class StringBuilder
{
public StringBuilder Append(ReadOnlySpan<char> value);
public StringBuilder Insert(int index, ReadOnlySpan<char> value);
public void CopyTo(int sourceIndex, Span<char> destination, int count);
…
}
}