Macro not working in properly

help
1

i have macros

src/lib.rs

use core::mem::transmute;

#[macro_export]
macro_rules! msg {
    [$cls:ident $sel:ident] => {
        $crate::__msg_send!{$cls, $sel}
    };
    [$cls:ident $($sel_and_arg:tt)+] => {
        $crate::__msg_parse!{$cls $($sel_and_arg)+}
    };
}

#[macro_export]
macro_rules! __msg_parse {
    {$cls:ident $($sel:ident : $arg:expr)+} => {
        $crate::__msg_send!{$cls $($sel)+ $($arg)+}
    };
}

#[macro_export]
macro_rules! __msg_send {
    {$cls:ident $sel:ident} => {{
        let cls = concat!(stringify!($cls), "\0");
        let sel = concat!(stringify!($sel), "\0");
        $crate::TupleFn::call((cls, sel))
    }};
    {$cls:ident $($sel:ident)+ $($arg:expr)+} => {{
        let cls = concat!(stringify!($cls), "\0");
        let sel = concat!($(stringify!($sel), ":"),+, "\0");
        $crate::TupleFn::call((cls, sel $(, $arg)*))
    }};
}

pub unsafe trait TupleFn<Output> {
    fn call(self) -> Output;
}

unsafe impl<A, B, Output> TupleFn<Output> for (A, B) {
    fn call(self) -> Output {
        let f = unsafe { transmute::<unsafe extern "C" fn(),unsafe extern "C" fn(A, B) -> Output>(objc_msgSend as unsafe extern "C" fn()) };
        let (cls, sel) = self;
        unsafe { f(cls, sel) }
    }
}

unsafe impl<A, B, C, Output> TupleFn<Output> for (A, B, C) {
    fn call(self) -> Output {
        let f = unsafe { transmute::<unsafe extern "C" fn(),unsafe extern "C" fn(A, B, C) -> Output>(objc_msgSend as unsafe extern "C" fn()) };
        let (cls, sel, arg1) = self;
        unsafe { f(cls, sel, arg1) }
    }
}

#[link(name = "objc")]
unsafe extern "C" {
    pub unsafe fn objc_msgSend();
}

the macros work great as seen in the following

src/main.rs

fn main() {
    msg![Alphabet A: 1];
}

until we do

src/main.rs

fn main() {
    let a = 1;
    msg![Alphabet A: a];
}

then i get the error

leftover tokens rust-analyzer(macro-error)

pls somebody help me
p.s. if not obvious this macro is going to be used to interface objective c and eventually create an app, window, etc.

2

Is it only rust-analyzer, or does the code also not compile successfully?

3

does not compile

4

In this case, could you also share the compilation error (as e.g. obtained via cargo check)?