“特质绑定std :: fmt :: Display不满意”是什么意思？

Question

My code:

extern crate time;

fn main() {
    println!("{}", time::get_time());
}

My error is:

Error 'the trait bound time::Timespec: std::fmt::Display is not satisfied

Answer 1

println! is a macro to do formatted output. {} is used to print a value that implements the Display trait. The error is saying that Timespec does not implement the Display trait, so it cannot be used with {} .

You can use {:?} instead of {} . {:?} is used to print a value that implements Debug trait and Timespec implements it.

Consider reading the fmt module documentation, it explain this in detail.