Macro require 

macro_rules! require {
    ($condition:expr) => { ... };
    ($condition:expr, $message:tt) => { ... };
}

Verify inputs and conditions

Result

If the condition was not satisfied, the execution will be stopped with error code 300 (RuntimeError::Exception)

Usage

use we_cdk::*;

#[action]
fn _constructor() {
    let balance = get_balance!(this);
    require!(balance > 42);
}

#[action]
fn require_with_message() {
    let balance = get_balance!(this);
    require!(balance > 1337, "Balance is less than 1337!");
}