#[deriving(ToStr)] doesn't work in std

[Kimundi]

Maybe I'm missing some magic incantation, but adding a #[deriving(ToStr)] to a type in std (here: rt::io::IoError) seems just to leads to these errors for me:

.../rust/src/libstd/rt/io/mod.rs:332:11: 332:16 error: unresolved import: could not find `to_str` in `std`.
.../rust/src/libstd/rt/io/mod.rs:332 #[deriving(ToStr)]
                                                ^~~~~
.../rust/src/libstd/rt/io/mod.rs:332:11: 332:16 error: use of undeclared module `::std::to_str`
.../rust/src/libstd/rt/io/mod.rs:332 #[deriving(ToStr)]
                                                ^~~~~
.../rust/src/libstd/rt/io/mod.rs:332:11: 332:16 error: attempt to implement a nonexistent trait `std::to_str::ToStr`
.../rust/src/libstd/rt/io/mod.rs:332 #[deriving(ToStr)]
                                                ^~~~~

[huonw]

This would be solved by adding a way to specify the path to std and extra, since it's currently just taken to be ::std::..., e.g. at the top of the appropriate crate

// in std
#[deriving_path(std="")];

// in extra
#[deriving_path(extra="")];

These would be std and extra if not specified, so the behaviour doesn't change. (And this might be useful as #[syntaxext_path] since other syntax extensions also assume ::std::....)

[emberian]

Visiting for triage. Is this still an issue, @huonw?

[sfackler]

If this isn't already working, this is easily fixable by adding pub use to_str to std::std.