| // Copyright 2014-2015 The Rust Project Developers. See the COPYRIGHT |
| // file at the top-level directory of this distribution and at |
| // http://rust-lang.org/COPYRIGHT. |
| // |
| // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or |
| // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license |
| // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your |
| // option. This file may not be copied, modified, or distributed |
| // except according to those terms. |
| |
| /// Creates a `Vec` containing the arguments. |
| /// |
| /// `vec!` allows `Vec`s to be defined with the same syntax as array expressions. |
| /// There are two forms of this macro: |
| /// |
| /// - Create a `Vec` containing a given list of elements: |
| /// |
| /// ``` |
| /// let v = vec![1, 2, 3]; |
| /// assert_eq!(v[0], 1); |
| /// assert_eq!(v[1], 2); |
| /// assert_eq!(v[2], 3); |
| /// ``` |
| /// |
| /// - Create a `Vec` from a given element and size: |
| /// |
| /// ``` |
| /// let v = vec![1; 3]; |
| /// assert_eq!(v, [1, 1, 1]); |
| /// ``` |
| /// |
| /// Note that unlike array expressions this syntax supports all elements |
| /// which implement `Clone` and the number of elements doesn't have to be |
| /// a constant. |
| /// |
| /// This will use `clone()` to duplicate an expression, so one should be careful |
| /// using this with types having a nonstandard `Clone` implementation. For |
| /// example, `vec![Rc::new(1); 5]` will create a vector of five references |
| /// to the same boxed integer value, not five references pointing to independently |
| /// boxed integers. |
| #[cfg(not(test))] |
| #[macro_export] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| #[allow_internal_unstable] |
| macro_rules! vec { |
| ($elem:expr; $n:expr) => ( |
| $crate::vec::from_elem($elem, $n) |
| ); |
| ($($x:expr),*) => ( |
| <[_]>::into_vec(box [$($x),*]) |
| ); |
| ($($x:expr,)*) => (vec![$($x),*]) |
| } |
| |
| // HACK(japaric): with cfg(test) the inherent `[T]::into_vec` method, which is |
| // required for this macro definition, is not available. Instead use the |
| // `slice::into_vec` function which is only available with cfg(test) |
| // NB see the slice::hack module in slice.rs for more information |
| #[cfg(test)] |
| macro_rules! vec { |
| ($elem:expr; $n:expr) => ( |
| $crate::vec::from_elem($elem, $n) |
| ); |
| ($($x:expr),*) => ( |
| $crate::slice::into_vec(box [$($x),*]) |
| ); |
| ($($x:expr,)*) => (vec![$($x),*]) |
| } |
| |
| /// Use the syntax described in `std::fmt` to create a value of type `String`. |
| /// See `std::fmt` for more information. |
| /// |
| /// # Examples |
| /// |
| /// ``` |
| /// format!("test"); |
| /// format!("hello {}", "world!"); |
| /// format!("x = {}, y = {y}", 10, y = 30); |
| /// ``` |
| #[macro_export] |
| #[stable(feature = "rust1", since = "1.0.0")] |
| macro_rules! format { |
| ($($arg:tt)*) => ($crate::fmt::format(format_args!($($arg)*))) |
| } |