error not-implemented

Конструкция допустима по стандарту, но пока не поддерживается реализацией.

What it means#

The program is valid according to the standard, but the current stage of the compiler does not implement the construct yet. This is not a mistake in your program: the standard describes the full language, and the implementation grows towards it. The message names the unsupported construct.

Example#

fn main() io {
  fn helper() -> i32 { 1 }      // <- not-implemented (a local `fn` is not supported yet)
  print("{helper()}")
}

not-implemented

How to fix#

fn helper() -> i32 { 1 }

fn main() io {
  print("{helper()}")
}

Rewrite the construct with features the current stage supports (here, a for loop with a where filter, §5.6), or wait for the stage that implements it. Which constructs are affected depends on the compiler version.

See also#

• syntax