Multi-statement Macros in C++
c++, macros
Solution
For a multi-line macro you need to add a `\` character to the end of all but the last line to tell the macro processor to continue parsing the macro on the next line, like so:
#define MATCH_SYMBOL( symbol, token) \
if(something == symbol){ \
if( symbol == '-'){ \
}else if (symbol != '-'){ \
} \
other steps; \
}
Right now, it's trying to interpret it as a 1-line macro and then some actual code at the top of your file, which isn't what you want:
#define MATCH_SYMBOL( symbol, token)
// and then... wrongly thinking this is separate...
if(something == symbol){ // symbol was never defined, because the macro was never used here!
if( symbol == '-'){
}else if (symbol != '-'){
}
other steps;
}
Problem
In C++, is it possible to make a multi-statement macro with nested if statements inside of it like the one below? I've been attempting it for a while now and I'm getting a scope issue for the second if statement not being able to see 'symbol'. Maybe I need to understand macros further. ``` #define MATCH_SYMBOL( symbol, token) if(something == symbol){ if( symbol == '-'){ }else if (symbol != '-'){ } other steps; } ```