Error

The error "no rules expected the token" occurs when a macro invocation uses syntax that doesn't match any of the macro's defined patterns, often due to missing delimiters or incorrect token sequences. Ensure your macro call matches the pattern defined in the macro body, such as using parentheses () or braces {} consistently as expected by the macro definition.

// Correct usage matching a macro expecting parentheses
my_macro!(arg1, arg2);

// Incorrect usage causing the error if macro expects parentheses
my_macro! { arg1, arg2 } 

The "no rules expected the token" error in a macro means your code doesn't fit the pattern the macro was designed to accept. Think of it like trying to put a square peg in a round hole; the macro expects specific shapes (syntax) and your input doesn't match. Fix it by checking the macro's definition and adjusting your call to use the correct brackets or structure.