use assert_no_alloc::*; #[cfg(debug_assertions)] #[global_allocator] static A: AllocDisabler = AllocDisabler; fn main() { println!("Alloc is allowed. Let's allocate some memory..."); let mut vec_can_push = Vec::new(); vec_can_push.push(42); println!(); let fib5 = assert_no_alloc(|| { println!("Alloc is forbidden. Let's calculate something without memory allocations..."); fn fib(n: u32) -> u32 { if n<=1 { 1 } else { fib(n-1) + fib(n-2) } } fib(5) }); println!("\tSuccess, the 5th fibonacci number is {}", fib5); println!(); assert_no_alloc(|| { println!("Alloc is forbidden. Let's allocate some memory..."); let mut vec_cannot_push = Vec::new(); vec_cannot_push.push(42); // panics }); println!("This will not be executed if the above allocation has aborted."); }