E0020

Warning name: deprecated

Deprecated API usage.

This warning is emitted when code uses APIs marked as deprecated.

Erroneous example

lib/top.mbt

///|
#deprecated("Use `greet` instead")
pub fn greeting() -> String {
  "Hello!"
}

///|
pub fn greet() -> String {
  "Hello!"
}

top.mbt

///|
fn main {
  println(@lib.greeting())
  //      ^~~~~~~~ Warning (deprecated): Use `greet` instead
}

Suggestion

Migrate to the suggested APIs:

top.mbt

///|
fn main {
  println(@lib.greet())
}