Rust large array: thread 'main' has overflowed its stack

Asked Mar 20 '20 at 15:50

Active Mar 20 '20 at 15:50

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New to Rust, and ran into this error thread 'main' has overflowed its stack for this code:

fn main() {
    const N: usize = 10_000_000;
    let mut a: [u8; N]= [1; N];
    a[0] = 0;
}

It is ok for N = 1_000_000. Is there a better way to allocate long array?

asked Mar 20 '20 at 15:50

Jingshao Chen

3

The stack tends to not like huge objects. Use a `Vec` instead, which will allocate the array on the heap and your problem will go away. – mcarton Mar 20 '20 at 15:59
Nice! Vec solves the problem – Jingshao Chen Mar 20 '20 at 16:11
1

To be more specific, `let mut a = vec![1u8; N];` fixed it. Because Vec is allocated in the heap, which can grow much larger. – Jingshao Chen Mar 20 '20 at 17:22

0 Answers0