Macro size_of_expr

macro_rules! size_of_expr {
    ($expr: expr) => { ... };
}

Returns the size of an expression in bytes.

• The expression will not be evaluated.
• This can be used in const contexts.

Example

async fn f() {
    let x = 1;
    core::future::ready(()).await;
}
const SIZE: usize = size_of_expr!(f());
assert_eq!(SIZE, 2);

Features

Makes use of unreachable_unchecked if the unsafe_hint feature is enabled.