Macro assert_fn_eq_x_as_result 

macro_rules! assert_fn_eq_x_as_result {
    ($a_function:path, $a_param:expr, $b_expr:expr $(,)?) => { ... };
    ($a_function:path, $b_expr:expr $(,)?) => { ... };
}

Assert a function output is equal to an expression.

Pseudocode:
function(a) = b

• If true, return Result Ok(a).

• Otherwise, return Result Err(message).

This macro is useful for runtime checks, such as checking parameters, or sanitizing inputs, or handling different results in different ways.

Module macros

• assert_fn_eq_x
• assert_fn_eq_x_as_result
• debug_assert_fn_eq_x