~"" == "" fails to borrow

[ghost]

If I use "Function eq - Bytewise string equality", only I put mutable and also there is limited type..

hmm.. Isn't here any good way to compare variables?

[graydon]

There are no mutable strings. If you mean "" and ~"", the comparison failing between them presently is a bug in type inference surrounding the == operator and will eventually be fixed. Or at least this is Niko's assessment. I'm assigning to him in the meantime but I expect this bug will solve itself. You can work around it using str::eq_slice() for now (which itself should be merged with str::eq). Apologies, the str module is still in transition from earlier work on it during the summer.

[nikomatsakis]

I think this is working as designed. If you need to compare slices to unique strings, you want str::eq(), == is used for values of the same type. I originally thought we could make it otherwise but I now believe we cannot.