Extension traits for many standard/core library types/traits. and other miscelaneuous types / traits / functions / macros.
Adding as dependency
This crate requires cargo features for enabling items, to get all of them you can use:
[]
= "1.0"
= ["std", "all_items"]
The "std" feature is required to enable impls and items that use [std] types,
otherwise only the [core] library is supported.
For enabling features individually, look here.
This crate currently requires cargo features to use newer language features,
Examples
Showcasing some features from this crate.
quasiconst, generic constants.
The [quasiconst] macro allows emulating generic constants by generating a
zero-sized generic type that implements the [ConstVal] trait,
the preferred way to get its value is the [getconst] macro.
This example demonstrates how you can use them to declare a generic VTABLE constant.
use core_extensions::{getconst, quasiconst};
use std::fmt::{self, Debug};
quasiconst!{ pub const VTABLE<T: Debug>: &'static Vtable = &Vtable { size: std::mem::size_of::(), align: std::mem::align_of::(), drop: drop_erased::, fmt: debug_fmt_erased::, }; }
fn main() {
const VTABLE_U8: &'static Vtable = getconst!(VTABLE); assert_eq!(VTABLE_U8.size, 1); assert_eq!(VTABLE_U8.align, 1);
const VTABLE_USIZE: &'static Vtable = getconst!(VTABLE); assert_eq!(VTABLE_USIZE.size, std::mem::size_of::()); assert_eq!(VTABLE_USIZE.align, std::mem::align_of::());
const VTABLE_STRING: &'static Vtable = getconst!(VTABLE<&str>); assert_eq!(VTABLE_STRING.size, std::mem::size_of::() * 2); assert_eq!(VTABLE_STRING.align, std::mem::align_of::());
}
pub struct Vtable { pub size: usize, pub align: usize, pub drop: unsafe fn(*mut ()), pub fmt: unsafe fn(*const (), &mut fmt::Formatter<'_>) -> fmt::Result, }
unsafe fn drop_erased(ptr: *mut ()) { std::ptr::drop_in_place(ptr as *mut T) }
unsafe fn debug_fmt_erased(ptr: const (), f: &mut fmt::Formatter<'_>) -> fmt::Result where T: Debug, { let this = unsafe{ &(ptr as *const T) };
Debug::fmt(this, f) }
# no-std support
This crate works in `#![no_std]` contexts by default.
# Supported Rust versions
This crate support Rust back to 1.41.0,
requiring cargo features to use language features from newer versions.
<span id = "cargo-features-section"></span>
# Cargo Features
### crate features
The `"all_items"` feature enables all of these features,
you can use it instead of the ones below if you don't mind longer compile-times:
- `"bools"`: Enables the [`BoolExt`] trait, extension trait for `bool`.
- `"callable"`: Enables the [`callable`] module,
with stably implementable equivalents of the `Fn*` traits.
- `"collections"`: Enables the [`collections`] module, with traits for collection types.
- `"const_default"`:
Enables the [`ConstDefault`] trait, and [`const_default`] macro,
for a `const` equivalent of the `Default` trait.
- `"const_val"`:
Enables the [`ConstVal`] trait (for types that represent constants),
[`getconst`] macro (for getting the [`ConstVal::VAL`] associated constant),
and [`quasiconst`] macro (for declaring types that emulate generic constants).
Enables the `"generics_parsing"` feature.
- `"macro_utils`: Enables the [`rewrap_macro_parameters`] macro.
- `"generics_parsing"`:
Enables the [`parse_generics`], [`parse_generics_and_where`],
[`split_generics_and_where`],
[`parse_split_generics`], and [`parse_split_generics_and_where`] macros.
These allow macros to parse items with generic parameters.
- `"item_parsing"`:
Enables the `"macro_utils` and `"generics_parsing"` features.
Enables the [`impl_parse_generics`] and [`impl_split`] macros.
- `"integers"`: Enables the [`integers`] module, with extension traits for integer types.
- `"iterators"`: Enables the [`iterators`] module,
with the [`IteratorExt`] extension trait for iterators, and a few iterator types.
- `"marker_type"`: Enables the [`MarkerType`] trait,
for trivially constructible, zero-sized, and aligned-to-1 types.
- `"on_drop"`: Enables the [`RunOnDrop`] type,
a wrapper type that runs a closure at the end of the scope.
- `"option_result"`: Enables the [`option_result_ext`] module,
with traits for `Option` and `Result`-like types.
- `"phantom"`: Enables the [`phantom`] module(with `PhantomData`-related items),
[`expr_as_phantom`] macro,[`map_phantomdata`] macro, and [`return_type_phantom`] macro.
- `"self_ops"`: Enables the [`SelfOps`] trait, an extension trait for all types.
It primarily has methods for calling free functions as methods.
- `"slices"`:
Enables the [`slices`] module, with extension traits for `[T]` and `str` slices.
- `"strings"`:
Enables the [`strings`] module, with the [`StringExt`] extension trait for strings.
- `"transparent_newtype"`: Enables the [`transparent_newtype`] module,
with extension traits and functions for `#[repr(transparent)]` newtypes with public fields.
- `"type_asserts"`: Enables the [`type_asserts`] module, with type-level assertiosn,
most useful in tests.
- `"type_identity"`: Enables the [`TypeIdentity`] trait,
for proving that two types are equal, and converting between them in a generic context.
- `"type_level_bool"`: Enables the [`type_level_bool`] module,
which encodes `bool`s on the type-level.
- `"void"`: Enables the [`Void`] type, a type that can't be constructed,
for encodign impossible situations.
<span id = "cargo-features-lang-section"></span>
### Rust Version numbers
These features enable code that require some Rust version past the minimum supported one:
- "rust_1_46": Makes [`TransparentNewtype`] and [`TypeIdentity`]
associated functions that take `Rc<Self>` or `Arc<Self>` callable as methods.
- "rust_1_51": Enables the "rust_1_46" feature, and impls of traits for all array lengths.
### Support for other crates
All of these are disabled by default:
- `"std"`: Enables `std` library support. Implies the `"alloc"` feature.
- `"alloc"`: Enables `alloc` library support.
- `"serde_"`: Enables serde support.
### Miscelaneous features
`"track_caller"`:
Enables the "rust_1_46" feature.
Changes `ResultLike` to allow getting the caller location in `ResultLike::into_result_`,
and makes `IsNoneError` store where it was constructed.
`"docsrs"`: Used to document the required features in docs.rs, requires Rust nightly.
Doesn't enable any items itself.
[`collections`]: ./collections/index.html
[`callable`]: ./callable/index.html
[`integers`]: ./integers/index.html
[`iterators`]: ./iterators/index.html
[`option_result_ext`]: ./option_result_ext/index.html
[`phantom`]: ./phantom/index.html
[`slices`]: ./slices/index.html
[`strings`]: ./strings/index.html
[`transparent_newtype`]: ./transparent_newtype/index.html
[`type_asserts`]: ./type_asserts/index.html
[`type_level_bool`]: ./type_level_bool/index.html
[`rewrap_macro_parameters`]: ./macro.rewrap_macro_parameters.html
[`parse_generics`]: ./macro.parse_generics.html
[`parse_generics_and_where`]: ./macro.parse_generics_and_where.html
[`split_generics_and_where`]: ./macro.split_generics_and_where.html
[`parse_split_generics`]: ./macro.parse_split_generics.html
[`parse_split_generics_and_where`]: ./macro.parse_split_generics_and_where.html
[`impl_parse_generics`]: ./macro.impl_parse_generics.html
[`impl_split`]: ./macro.impl_split.html
[`BoolExt`]: ./trait.BoolExt.html
[`ConstDefault`]: ./trait.ConstDefault.html
[`ConstVal`]: ./trait.ConstVal.html
[`ConstVal::VAL`]: ./trait.ConstDefault.html#associatedconstant.VAL
[`MarkerType`]: ./trait.MarkerType.html
[`SelfOps`]: ./trait.SelfOps.html
[`TypeIdentity`]: ./trait.TypeIdentity.html
[`TransparentNewtype`]: ./transparent_newtype/trait.TransparentNewtype.html
[`RunOnDrop`]: ./struct.RunOnDrop.html
[`Void`]: ./enum.Void.html
[`const_default`]: ./macro.const_default.html
[`getconst`]: ./macro.getconst.html
[`quasiconst`]: ./macro.quasiconst.html
[`expr_as_phantom`]: ./macro.expr_as_phantom.html
[`map_phantomdata`]: ./macro.map_phantomdata.html
[`return_type_phantom`]: ./macro.return_type_phantom.html
[`IteratorExt`]: ./iterators/trait.IteratorExt.html
[`StringExt`]: ./strings/trait.StringExt.html
[`core`]: https://doc.rust-lang.org/core/
[`std`]: https://doc.rust-lang.org/std/