Skip to content

Implement vec! macro #40

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
merged 9 commits into from
May 27, 2025
Merged
Show file tree
Hide file tree
Changes from 6 commits
Commits
File filter

Filter by extension

Filter by extension

Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
5 changes: 4 additions & 1 deletion src/lib.rs
Original file line number Diff line number Diff line change
Expand Up @@ -2,6 +2,9 @@
#![deny(missing_docs)]
#![doc = include_str!("../README.md")]

#[macro_use]
mod macros;

use core::mem::MaybeUninit;
use core::{cmp, error, fmt, slice};

Expand Down Expand Up @@ -60,7 +63,7 @@ impl<T, const CAPACITY: usize> Vec<T, CAPACITY> {
pub const fn new() -> Self {
assert!(CAPACITY > 0, "CAPACITY must be greater than 0");

// SAFETY: The elements in the array are not accessed before beign initialized.
// SAFETY: The elements in the array are not accessed before being initialized.
let data = unsafe { MaybeUninit::<[MaybeUninit<T>; CAPACITY]>::uninit().assume_init() };
Self { data, length: 0 }
}
Expand Down
132 changes: 132 additions & 0 deletions src/macros.rs
Original file line number Diff line number Diff line change
@@ -0,0 +1,132 @@
/// Creates new vector.
///
/// # Forms
///
/// - `vec![T; CAPACITY]`: Creates an empty `Vec<T, CAPACITY>` with maximum `CAPACITY` elements of type `T`.
/// - `vec![x, y, z]`: Creates a `Vec` initialized with the given values. The capacity is inferred from the number of elements.
/// - `vec![CAPACITY; x, y, z]`: Creates a `Vec` with given `CAPACITY`, initialized with the given values.
/// - `vec![T; CAPACITY; LENGTH]`: Creates a `Vec<T, CAPACITY>` with maximum `CAPACITY` elements of type `T` and initialized with default `LENGTH` elements.
///
/// # Panics
///
/// - If `CAPACITY == 0`. Zero-capacity vectors are not supported.
/// - If the number of elements used to initialize the vector is larger than the given `CAPACITY`.
/// - If the given initial `LENGTH` is larger than the given `CAPACITY`.
///
/// # Examples
///
/// Create an empty vector with capacity:
///
/// ```rust
/// let vec = static_vector::vec![i32; 10];
/// assert!(vec.is_empty());
/// ```
///
/// Create a vector from elements:
///
/// ```rust
/// let vec = static_vector::vec![1, 2, 3];
/// assert_eq!(vec.as_slice(), &[1, 2, 3]);
/// ```
///
/// Create a vector with a specific capacity and elements:
/// ```rust
/// let vec = static_vector::vec![10; 1, 2, 3];
/// assert_eq!(vec.as_slice(), &[1, 2, 3]);
/// ```
///
/// Create a vector with a specific type, capacity, length, and default values:
/// ```rust
/// let vec = static_vector::vec![i32; 10; 3];
/// assert_eq!(vec.as_slice(), &[0, 0, 0]);
/// ```
#[macro_export]
macro_rules! vec {
($type:ty; $capacity:literal) => {
$crate::Vec::<$type, $capacity>::new()
};

($($value:expr),+ $(,)?) => {
{
let mut vec = $crate::Vec::<_, { [$($value),+].len() }>::new();
vec.extend_from_slice(&[$($value),+]).expect("length matches capacity");
vec
}
};

($capacity:literal; $($value:expr),+ $(,)?) => {
{
let mut vec = $crate::Vec::<_, $capacity>::new();
vec.extend_from_slice(&[$($value),+]).expect("length is less than or equal to capacity");
vec
}
};

($type:ty; $capacity:literal; $length:literal) => {
{
let mut vec = $crate::Vec::<$type, $capacity>::new();
vec.set_len($length).expect("length is less than or equal to capacity");
vec
}
};
}

#[cfg(test)]
mod tests {
#[test]
fn vec_with_type_and_capacity() {
let vec = vec![i32; 10];
assert_eq!(vec.capacity(), 10);
assert!(vec.is_empty());
}

#[test]
#[should_panic(expected = "CAPACITY must be greater than 0")]
fn vec_with_type_and_capacity_zero() {
let _ = vec![i32; 0];
}

#[test]
fn vec_with_elements() {
let vec = vec![1, 2, 3];
assert_eq!(vec.capacity(), 3);
assert_eq!(vec.len(), 3);
assert_eq!(vec.as_slice(), &[1, 2, 3]);
}

#[test]
fn vec_with_capacity_and_elements() {
let vec = vec![10; 1, 2, 3];
assert_eq!(vec.capacity(), 10);
assert_eq!(vec.len(), 3);
assert_eq!(vec.as_slice(), &[1, 2, 3]);
}

#[test]
#[should_panic(expected = "length is less than or equal to capacity: CapacityError")]
fn vec_with_more_elements_than_capacity() {
let _ = vec![2; 1, 2, 3];
}

#[test]
fn vec_with_capacity_and_length() {
let vec = vec![i32; 10; 3];
assert_eq!(vec.capacity(), 10);
assert_eq!(vec.len(), 3);
assert_eq!(vec.as_slice(), &[0, 0, 0]);
}

#[test]
fn vec_with_capacity_and_length_when_length_is_equal_to_capacity() {
let vec = vec![i32; 3; 3];
assert_eq!(vec.capacity(), 3);
assert_eq!(vec.len(), 3);
assert_eq!(vec.as_slice(), &[0, 0, 0]);
}

#[test]
#[should_panic(expected = "length is less than or equal to capacity: CapacityError")]
fn vec_with_capacity_and_length_when_length_is_greater_than_capacity() {
let _ = vec![i32; 10; 30];
}
}