Function references are a complex type that can reference any function or closure.

The type keyword is functionref and needs to include any parameter types and optionally return types.

void function CallDelayed( void functionref() fn )
 wait 1

You can call functionrefs like a regular function. The return type of a functionref will default to var if omitted. Omitting the return type is only possible in untyped files.

Parameter names are optional in functionrefs. Otherwise the parameter syntax is like in regular functions.

void function Example( int n, ... ) {}

void functionref( int, ... ) fn = Example