Expand description
Creates corresponding macro definitions for constants, allowing the value of the constants to be used in the context of other macros.
§Examples
ⓘ
macro_const! {
const FILE: &str = "message.txt";
}
println!("Contents: {}", include_str!(FILE!()));
println!("File: {}", FILE);
Doc comments can be added as well. The documentation for the constant will be added to the
generated macro verbatim. To export the generated macro, simply add the #[macro_export]
attribute to the constant definition.
macro_const! {
/// The API base URL.
#[macro_export]
pub const BASE_URL: &str = "https://myapi.io/";
/// The current supported API version.
pub const API_VERSION: &str = "v1";
}
assert_eq!("https://myapi.io/v1", concat!(BASE_URL!(), API_VERSION!()));
Macros§
- macro_
const - Generates corresponding macros for constants that evaluate to the same values as the constants.