auto merge of #11988 : cmr/rust/11668-squash, r=alexcrichton

Author: bors

doc/rust.md

@@ -482,7 +482,7 @@ syntax, and yet are not implementable as functions. Instead, they are given
 names, and invoked through a consistent syntax: `name!(...)`. Examples
 include:
 
-* `fmt!` : format data into a string
+* `format!` : format data into a string
 * `env!` : look up an environment variable's value at compile time
 * `file!`: return the path to the file being compiled
 * `stringify!` : pretty-print the Rust expression given as an argument
@@ -1975,10 +1975,6 @@ Supported traits for `deriving` are:
 * `Rand`, to create a random instance of a data type.
 * `Default`, to create an empty instance of a data type.
 * `Zero`, to create an zero instance of a numeric data type.
-* `ToStr`, to convert to a string. For a type with this instance,
-  `obj.to_str()` has similar output as `fmt!("%?", obj)`, but it differs in that
-  each constituent field of the type must also implement `ToStr` and will have
-  `field.to_str()` invoked to build up the result.
 * `FromPrimitive`, to create an instance from a numeric primitve.
 
 ### Stability