user0/rust
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

remove subtyping from coercions, it's something else

Browse source
This commit is contained in:
Alexis Beingessner 2015-07-20 16:18:52 -07:00
parent 5f02de3c22
commit 3f8e029bed
1 changed files with 5 additions and 7 deletions
Download patch file Download diff file Expand all files Collapse all files

12
src/doc/tarpl/coercions.md
View file

@ -1,16 +1,16 @@
% Coercions
Types can implicitly be coerced to change in certain contexts. These changes are
generally just *weakening* of types, largely focused around pointers and lifetimes.
They mostly exist to make Rust "just work" in more cases, and are largely harmless.
generally just *weakening* of types, largely focused around pointers and
lifetimes. They mostly exist to make Rust "just work" in more cases, and are
largely harmless.
Here's all the kinds of coercion:
Coercion is allowed between the following types:
* Subtyping: `T` to `U` if `T` is a [subtype][] of `U`
* Transitivity: `T_1` to `T_3` where `T_1` coerces to `T_2` and `T_2` coerces to `T_3`
* Transitivity: `T_1` to `T_3` where `T_1` coerces to `T_2` and `T_2` coerces to
`T_3`
* Pointer Weakening:
* `&mut T` to `&T`
* `*mut T` to `*const T`
@ -68,5 +68,3 @@ fn main() {
<anon>:10 foo(t);
^~~
```
[subtype]: subtyping.html