print or eprint of something it cannot print

Built from the repository at commit a8614dc.

print and eprint take exactly one argument, an i64, a u8, a bool, a char or a string, and write it on its own line: print to standard output, eprint to standard error. The message names the function that was called.

Why

An object, an optional or a call that returns nothing has no one way to be printed. A program prints the fields or the payload it means, one print or eprint each.

Broken

class Point {
    x: i64
}

fn main() {
    let p = Point(x: 1)
    print(p)
}

What sisu says

error[E0059]: cannot print `Point`
 --> E0059.sisu:7:11
  |
7 |     print(p)
  |           ^
  |
  = help: `print` takes one `i64`, `u8`, `f64`, `bool`, `char` or `string`

sisu: 1 error
sisu: for more on a code, run `sisu explain <code>`: E0059

Fixed

class Point {
    x: i64
}

fn main() {
    let p = Point(x: 1)
    print(p.x)
}

Related

• E0060: print or eprint of an array.