Why char[] is not @nogc on this case

[SrMordred]

On Friday, 25 May 2018 at 00:04:10 UTC, Adam D. Ruppe wrote:
> On Thursday, 24 May 2018 at 23:55:24 UTC, SrMordred wrote:
>> //Error: @nogc delegate onlineapp.main.__lambda1 cannot call 
>> non- at nogc function std.range.chain!(char[], 
>> char[]).chain.Result.front
>>
>> Why?
>
> phobos automatically decodes utf8 into dchars. This can throw a 
> new utf exception.

Oh its the utf8 decode thing.
I forgot about it.
I thought that it only decodes when using strings and dchars.

Thanks!