The use of a GNU C extension for bloc expressions is immaterial to the
actual problem with C macros that the section tries to show so don’t
use it and instead use a plain C way of writing the macro.
mdbook has a lot of optional dependencies that we don't want, so instead
of using it directly, we re-build rustbook to use mdbook as a library.
For convenience' sake, we keep the same CLI interface as mdbook; the
only difference is that it only accepts build and test subcommands,
rather than the full range.
Fix short hand struct doc
Don't want to discredit @hngiang effort on this issue.
I just want to lend a hand to fix this issue #38830, it is a very nice feature and is seemingly completed.
Fixes#39096
r? @steveklabnik
Update if-let.md
Calling if-let a combination of if and let is confusing, as some may be led to believe that it's a literal combination, instead of syntactic sugar added to the language as a convenience. What's there to stop someone from thinking if-let is just if and let together?
I do think this article does a good job of implying what's really going on; however, I was only able to notice this after I had begun to understand if/while-let statements, courtesy of the Rust IRC chat.
Basically, this article lacks the clarity and explicitness an inexperienced programmer like me needs in order to understand the contents fully. This is shown by my inability to understand the if-let concept from this page of the Book alone.
I think convenience, sugar, and (if-let != if + let) should all be made mention of in a clear, explicit manner. I lack confidence in my understanding of this issue, so I wrote just enough to hopefully get my thoughts across.
rustdoc: fix doctests with non-feature crate attrs
Fixes#38129.
The book says that any top-level crate attributes at the beginning of a doctest are moved outside the generated `fn main`, but it was only checking for `#![feature`, not `#![`.
These attributes previously caused warnings but were then ignored, so in theory this could change the behavior of doctests in the wild.
Extend Cell to work with non-Copy types
I'm not sure that I did this right but all of the tests pass.
I also had to move the `new()` function so that `Cell`s with non-`Copy` `T`s could be created. That wasn't in the RFC but I assume it needed to be done?
Improve doc cfg(test) and tests directory
Hi,
I was facing a problem with my code organisation. I was using a tests directory and i defined some `#[cfg(test)]` in my `src/`. But i was not able to use it in my `tests` folder.
```bash
.
├── Cargo.lock
├── Cargo.toml
├── src
│ ├── lib.rs
│ └── test.rs
└── tests
└── x.rs
```
> src/lib.rs
```rust
pub mod test;
fn tesst() {
assert!(test::t());
}
```
> src/test.rs
```rust
pub fn t() -> bool { true }
```
> test/x.rs
```rust
extern crate testt;
use testt::test;
fn tesst() {
assert!(test::t());
}
```
I was unable to compile using `cargo test`:
```bash
error[E0432]: unresolved import `testt::test`
--> tests/x.rs:3:5
|
3 | use testt::test;
| ^^^^^^^^^^^ no `test` in `testt`
```
If i remove the `tests` directory everything works fine. To use an utils module in your `tests` directory, you need to create a module in the directory (like `tests/utils.rs`). My `tests/x.rs` look like this now:
```rust
extern crate testt;
mod utils;
fn tesst() {
assert!(utils::t());
}
```
And my tree:
```bash
.
├── Cargo.lock
├── Cargo.toml
├── src
│ └── lib.rs
└── tests
├── utils.rs
└── x.rs
```
I think that thing must be documented in the book.
Ping:
- @badboy : Because he's the one who showed me the path
- @shahn : Because he helped me too to find the solution
Signed-off-by: Freyskeyd <simon.paitrault@iadvize.com>
book: size and align in trait object vtables are used
The book currently claims that the `size` and `align` fields in the
trait object vtable are not used, but this is false. These two fields
are used by the stable `mem::size_of_val` and `mem::align_of_val`
functions.
See the `ty::TyDynamic` case of the `glue::size_and_align_of_dst`
function in librustc_trans, which is used to implement both intrinsics
in the unsized case.
r? @steveklabnik
book: match enum warning
Matching enums with named fields in the previous way yielded the "non_shorthand_field_patterns" warning.
The new code shows the shorthand syntax as well as field renaming, so it should be exhaustive ;-)
The book currently claims that the `size` and `align` fields in the
trait object vtable are not used, but this is false. These two fields
are used by the stable `mem::size_of_val` and `mem::align_of_val`
functions.
See the `ty::TyDynamic` case of the `glue::size_and_align_of_dst`
function in librustc_trans, which is used to implement both intrinsics
in the unsized case.
