Alex Crichton b78b749810 Remove all ToStr impls, add Show impls ... This commit changes the ToStr trait to: impl<T: fmt::Show> ToStr for T { fn to_str(&self) -> ~str { format!("{}", *self) } } The ToStr trait has been on the chopping block for quite awhile now, and this is the final nail in its coffin. The trait and the corresponding method are not being removed as part of this commit, but rather any implementations of the `ToStr` trait are being forbidden because of the generic impl. The new way to get the `to_str()` method to work is to implement `fmt::Show`. Formatting into a `&mut Writer` (as `format!` does) is much more efficient than `ToStr` when building up large strings. The `ToStr` trait forces many intermediate allocations to be made while the `fmt::Show` trait allows incremental buildup in the same heap allocated buffer. Additionally, the `fmt::Show` trait is much more extensible in terms of interoperation with other `Writer` instances and in more situations. By design the `ToStr` trait requires at least one allocation whereas the `fmt::Show` trait does not require any allocations. Closes #8242 Closes #9806		2014-02-23 20:51:56 -08:00
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lib.rs	Remove all ToStr impls, add Show impls	2014-02-23 20:51:56 -08:00