Macro delayload 

macro_rules! delayload {
    {$dll:literal {
        $(
            $(#[$a:meta])*
            $visibility:vis fn $name:ident($($params:ident : $types:ty),* $(,)?) -> $result:ty;
        )*
    }} => { ... };
    (@result_from_win32((i32), $val:expr)) => { ... };
    (@result_from_win32((u32), $val:expr)) => { ... };
    (@result_from_win32((DWORD), $val:expr)) => { ... };
    (@result_from_win32((HRESULT), $val:expr)) => { ... };
    (@result_from_win32(($t:tt), $val:expr)) => { ... };
}