E0210: A typed decorator in a composition

A typed decorator (a plain Go function of the decorated function's own type, func(func(int) int) func(int) int) depends on that type, so it can't be part of a composed decorator, which applies to functions of any type.

Wrong

decorator Fast = @logged @double

@Fast
func one() int { return 1 }

Right

decorator Fast = @logged

@Fast
@double
func one() int { return 1 }