Macro assertables::assert_option_none

macro_rules! assert_option_none {
    ($option:expr $(,)?) => { ... };
    ($option:expr, $($message:tt)+) => { ... };
}

Assert expression.is_none() is true.

• If true, return ().

• Otherwise, call panic! with a message and the values of the expressions with their debug representations.

Examples

let a: Option<i8> = Option::None;
assert_option_none!(a);

let a: Option<i8> = Option::Some(1);
assert_option_none!(a);
// assertion failed: `assert_option_none!(option)`
//      option label: `a`,
//      option debug: `Some(1)`,
//  option.is_none(): `false`

Module macros

• assert_option_none
• assert_option_none_as_result
• debug_assert_option_none