This should be called far less than it is because it does expensive OS
interactions and seeding of the internal RNG, `task_rng` amortises this
cost. The main problem is the name is so short and suggestive.
The direct equivalent is `StdRng::new`, which does precisely the same
thing.
The deprecation will make migrating away from the function easier.
This replaces it with a manual "task rng" using XorShift and a crappy
seeding mechanism. Theoretically good enough for the purposes
though (unique for tests).
This functionality is not super-core and so doesn't need to be included
in std. It's possible that std may need rand (it does a little bit now,
for io::test) in which case the functionality required could be moved to
a secret hidden module and reexposed by librand.
Unfortunately, using #[deprecated] here is hard: there's too much to
mock to make it feasible, since we have to ensure that programs still
typecheck to reach the linting phase.
It is often convenient to have forms of weak linkage or other various types of
linkage. Sadly, just using these flavors of linkage are not compatible with
Rust's typesystem and how it considers some pointers to be non-null.
As a compromise, this commit adds support for weak linkage to external symbols,
but it requires that this is only placed on extern statics of type `*T`.
Codegen-wise, we get translations like:
```rust
// rust code
extern {
#[linkage = "extern_weak"]
static foo: *i32;
}
// generated IR
@foo = extern_weak global i32
@_some_internal_symbol = internal global *i32 @foo
```
All references to the rust value of `foo` then reference `_some_internal_symbol`
instead of the symbol `_foo` itself. This allows us to guarantee that the
address of `foo` will never be null while the value may sometimes be null.
An example was implemented in `std::rt::thread` to determine if
`__pthread_get_minstack()` is available at runtime, and a test is checked in to
use it for a static value as well. Function pointers a little odd because you
still need to transmute the pointer value to a function pointer, but it's
thankfully better than not having this capability at all.
Thanks to @bnoordhuis for the original patch, most of this work is still his!
It is often convenient to have forms of weak linkage or other various types of
linkage. Sadly, just using these flavors of linkage are not compatible with
Rust's typesystem and how it considers some pointers to be non-null.
As a compromise, this commit adds support for weak linkage to external symbols,
but it requires that this is only placed on extern statics of type `*T`.
Codegen-wise, we get translations like:
// rust code
extern {
#[linkage = "extern_weak"]
static foo: *i32;
}
// generated IR
@foo = extern_weak global i32
@_some_internal_symbol = internal global *i32 @foo
All references to the rust value of `foo` then reference `_some_internal_symbol`
instead of the symbol `_foo` itself. This allows us to guarantee that the
address of `foo` will never be null while the value may sometimes be null.
An example was implemented in `std::rt::thread` to determine if
`__pthread_get_minstack()` is available at runtime, and a test is checked in to
use it for a static value as well. Function pointers a little odd because you
still need to transmute the pointer value to a function pointer, but it's
thankfully better than not having this capability at all.
Where ItemDecorator creates new items given a single item, ItemModifier
alters the tagged item in place. The expansion rules for this are a bit
weird, but I think are the most reasonable option available.
When an item is expanded, all ItemModifier attributes are stripped from
it and the item is folded through all ItemModifiers. At that point, the
process repeats until there are no ItemModifiers in the new item.
This is mostly a reaction to #12730. If we are going to keep calling them `char`, at least make it clear that they aren't characters but codepoint/scalar.
This seems to be causing some confusion among users. Rust's char are
not 8bit characters, but 32bit UCS-4 codepoint without surrogates
(Unicode Scalar Values as per Unicode glossary).
Make the doc more explicit about it.
Signed-off-by: Luca Bruno <lucab@debian.org>
* `Ord` inherits from `Eq`
* `TotalOrd` inherits from `TotalEq`
* `TotalOrd` inherits from `Ord`
* `TotalEq` inherits from `Eq`
This is a partial implementation of #12517.
If no arguments are given to `vec!` then no pushes are emitted and
so the compiler (rightly) complains that the mutability of `temp` is
never used.
This behaviour is rather annoying for users.
When using tasks in Rust, the expectation is that the runtime does not exit
before all tasks have exited. This is enforced in libgreen through the
`SchedPool` type, and it is enforced in libnative through a `bookkeeping` module
and a global count/mutex pair. Unfortunately, this means that a process which
originates with libgreen will not wait for spawned native tasks.
In order to fix this problem, the bookkeeping module was moved from libnative to
libstd so the runtime itself can wait for native tasks to exit. Green tasks do
not manage themselves through this bookkeeping module, but native tasks will
continue to manage themselves through this module.
Closes#12684
Using nanosleep() allows us to gracefully recover from EINTR because on error it
fills in the second parameter with the remaining time to sleep.
Closes#12689
The `std::cmp` functions are not correct for floating point types.
`min(NaN, 2.0)` and `min(2.0, NaN)` return different values, because
these functions assume a total order. Floating point types need special
`min`, `max` and `clamp` functions.
I added a new lint for variables whose names contain uppercase characters, since, by convention, variable names should be all lowercase. What motivated me to work on this was when I ran into something like the following:
```rust
use std::io::File;
use std::io::IoError;
fn main() {
let mut f = File::open(&Path::new("/something.txt"));
let mut buff = [0u8, ..16];
match f.read(buff) {
Ok(cnt) => println!("read this many bytes: {}", cnt),
Err(IoError{ kind: EndOfFile, .. }) => println!("Got end of file: {}", EndOfFile.to_str()),
}
}
```
I then got compile errors when I tried to add a wildcard match pattern at the end which I found very confusing since I believed that the 2nd match arm was only matching the EndOfFile condition. The problem is that I hadn't imported io::EndOfFile into the local scope. So, I thought that I was using EndOfFile as a sub-pattern, however, what I was actually doing was creating a new local variable named EndOfFile. This lint makes this error easier to spot by providing a warning that the variable name EndOfFile contains a uppercase characters which provides a nice hint as to why the code isn't doing what is intended.
The lint warns on local bindings as well:
```rust
let Hi = 0;
```
And also struct fields:
```rust
struct Something {
X: uint
}
```
- Added `TraitObject` representation to `std::raw`.
- Added doc to `std::raw`.
- Removed `Any::as_void_ptr()` and `Any::as_mut_void_ptr()`
methods as they are uneccessary now after the removal of
headers on owned boxes. This reduces the number of virtual calls needed from 2 to 1.
- Made the `..Ext` implementations work directly with the repr of
a trait object.
- Removed `Any`-related traits from the prelude.
- Added bench.
Bench before/after:
~~~
7 ns/iter (+/- 0)
4 ns/iter (+/- 0)
~~~
- Added `TraitObject` representation to `std::raw`.
- Added doc to `std::raw`.
- Removed `Any::as_void_ptr()` and `Any::as_mut_void_ptr()`
methods as they are uneccessary now after the removal of
headers on owned boxes. This reduces the number of virtual calls needed.
- Made the `..Ext` implementations work directly with the repr of
a trait object.
- Removed `Any`-related traits from the prelude.
- Added bench for `Any`
