Macro require_or_err

macro_rules! require_or_err {
    ($condition:expr, $msg:expr) => { ... };
}

require_or_err is a macro that checks if a given condition is met. If the condition is not met, the macro will return an error of type PreconditionFailedError with a specified message.

Arguments

• $condition: An expression that should evaluate to a boolean. This is the precondition that needs to be checked.
• $msg: A message that will be included in the PreconditionFailedError if the precondition is not met.

Errors

The macro returns an error of type PreconditionFailedError if the precondition $condition is not met, with an error message of the form: “Precondition failed: $msg”.