How/why is the rust compiler here ignoring that a template argument should have static lifetime?

Why does this rust code compile?

use std::fmt::Display;

fn g<T: 'static + Display>(t: T) {
    println!("{}", t);
}

fn t() {
    let x: i32 = 12;
    g(x);
}

fn main() {
    t();
}

Certainly in the function t() the local variable x is not static, yet the template specification of g seems to the demand that it must be. What am I misunderstanding?

For context: the example above is clearly very contrived. In a more complicated setting that I am working on, the compiler is forcing me to use T: 'static instead of just T, but I don’t want to use it just for static types. To my surprise however it just also works for non static variables and I am confused…

>Solution :

The bound T: 'static means that T only holds references that outlive the 'static lifetime (or more generally, all lifetime parameters on T do), not that T has to be a static item. And because i32 holds no references at all, this is trivially true. For reference, see the Rust reference and this handy guide, suggested by kmdreko.