Macro assure::assure_io

macro_rules! assure_io {
    ($x:expr $(,)?) => { ... };
    ($x:expr, $($arg:tt)+) => { ... };
}

Assure a condition is true.

If true, then return Ok(true).

Otherwise, return Err(std::io::Error …).

This macro has a second form, where a custom message can be provided.

Examples

assure_io!(true);
assure_io!(true, "message");