Macro magnus::rb_assert

macro_rules! rb_assert {
    ($expr:literal) => { ... };
    ($expr:literal, $($bindings:tt)*) => { ... };
    ($ruby:expr, $expr:literal) => { ... };
    ($ruby:expr, $expr:literal, $($bindings:tt)*) => { ... };
}

Asserts a Ruby expression evaluates to a truthy value.

This macro uses the Ruby power_assert gem that is part of the Ruby standard library to generate detailed failure messages.

magnus::rb_assert!("1 + 2 == 4");

Outputs:

thread 'main' panicked at '
1 + 2 == 4
  |   |
  |   false
  3', src/lib.rs:5:1

Panics

Panics if called from a non-Ruby thread.

Examples

magnus::rb_assert!("1 + 2 == 3");

Passing Ruby to avoid the Ruby thread check:

let ruby = magnus::Ruby::get().unwrap();
magnus::rb_assert!(ruby, "1 + 2 == 3");

Making local variables accessible to Ruby:

let a = 1;
let b = 2;
magnus::rb_assert!("a + b == 3", a, b);

Directly setting local variables:

magnus::rb_assert!("a + b == 3", a = 1, b = 2);