Print Vec using a placeholder

Asked Feb 08 '17 at 18:12

Active Feb 08 '17 at 18:15

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I am trying to print a Vec with variables of other datatypes:

let a = 4;
let b = vec![1,2,3,4];
let c = 3;

// printing input
println!("a: {0}, b: {1}, c: {2}", a, b, c);

but I get this error:

error[E0277]: the trait bound `std::vec::Vec<{integer}>: std::fmt::Display` is not satisfied
  --> src/main.rs:23:43
   |
23 |     println!("a: {0}, b: {1}, c: {2}", a, b, c);
   |                                           ^ trait `std::vec::Vec<{integer}>: std::fmt::Display` not satisfied
   |
   = note: `std::vec::Vec<{integer}>` cannot be formatted with the default formatter; try using `:?` instead if you are using a format string
   = note: required by `std::fmt::Display::fmt`

How do I print the Vec at a particular position in the output string?

edited Feb 08 '17 at 18:15

Shepmaster

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asked Feb 08 '17 at 18:12

Abhijay Ghildyal

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try using `:?` instead? – Josh Lee Feb 08 '17 at 18:13
1

`println!("a: {0}, b: {1:?}, c: {2}", a, b, c)`. Using the numbers in *this* case is silly though, you should just use `println!("a: {}, b: {:?}, c: {}", a, b, c)`. Refer to the [`fmt` module documentation](https://doc.rust-lang.org/stable/std/fmt/) for the complete list of what you can use to format and the appropriate syntax. – Shepmaster Feb 08 '17 at 18:15
how do I mention the position and :? together? – Abhijay Ghildyal Feb 08 '17 at 18:15
Thanks, this was helpful :) – Abhijay Ghildyal Feb 08 '17 at 18:18

Print Vec using a placeholder

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