Nobuyuki Iwanaga

CompilerFeatureRequiredAttribute (modreq を使えないところがあったり、modreq を出しちゃうとバイナリ互換壊しかねない場所で、普通に属性でやるとか言ってる) runtime/issues/66167

How can this treat item format? ```cs Log($"{i:X4}"); ```

I want to avoid string allocation of `i.ToString("X4")`. As an alternative idea, I want `ISpanFormattable` to be public. ```cs Span buffer = stackalloc char[4]; ((ISpanFormattablei)i).Format(buffer, out var written, "X4"); Log(buffer.AsSpan(0,...

I found spec https://github.com/dotnet/csharplang/pull/4486/files#diff-77eda16068bf940c41c3c540d5a0f74c1bfee4b56388b0bc4e59e037abaa9ec7R124-R125. This makes sense. Thank you.

It may already be too late, but can the parameter of `AppendLiteral` be `char` in addition to `string`? e.g. now, ```cs string s = $"{a}.{b}.{c}.{d}" ``` is lowered to ```cs...

> Is your concern performance? Yes. Is https://github.com/dotnet/runtime/pull/57217 as fast as `char` overload? Can `ldstr "."` (`var s = "."`) be optimized as fast as `ldc.i4.s 46` (`char c =...