Macro std_x::protected::fns

macro_rules! fns {
    (
      @Callback { $Callback : path }
      @Rest
      {
        $( #[ $Meta : meta ] )*
        $Vis : vis
        fn $Name : ident
        $( < $( $ParamName : ident $( : $ParamType : path )? ),* $(,)? > )?
        ( $( $In : tt )* )
        $( -> $Out : ty )?
        $( where $( $WhereParamName : ident $( : $WhereParamType : path )? ),*  $(,)? )?
        $Block : block

        $( $Rest : tt )*
      }
    ) => { ... };
    (
      @Callback { $Callback : path }
      @Rest {}
    ) => { ... };
    (
      @Callback { $Callback : path }
      @Rest { $( $Rest : tt )* }
    ) => { ... };
    (
      @Callback { $Callback : path }
      @Fns { $( $Fns : tt )* }
    ) => { ... };
}

Split functions.