How to properly use macros in C
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How to properly use macros in C
1–10 of 52 posts
Re: How to properly use macros in C
#2The problem with those explanations is that they are pointless. Unless you're still in college taking a C course, most people understand that macros are substitutions.
Re: How to properly use macros in C
#3Calling all C preprocessor directives (like #include and #if) "macros" makes me skeptical. Is this usage common?
Re: How to properly use macros in C
#4Calling all C preprocessor directives (like #include and #if) "macros" makes me skeptical. Is this usage common?
I haven't heard/seen it before either.
Re: How to properly use macros in C
#5answer: you don't
Re: How to properly use macros in C
#6The golden rule of macros is "always read the definition of macros before using." If you know it's a single value you're probably fine `#define MASK 0xf7`, but if it's a function macro or a normal macro that you know is doing more than inserting a literal in your code, it's best to glance at the macro to see what it does. Macros are useful for writing "shorthand C", but C should not be turned into a DSL, so you should think in actual C by converting the "shorthand C" in your head as you read/write it.
Re: How to properly use macros in C
#7Let's write pointless articles because reading basic programming books has become so unfashionable.
Re: How to properly use macros in C
#8If you're going to write a long lecture to people, it's helpful to do some Googling to fact-check your own understanding.
The claim that macros do not exist in other languages is incorrect. Every sensible assembly language compiler has macros to help the programmer with boilerplate.
The claim that multiline macros are a problem is correct. Suggesting that a workaround is to use a naming convention for such macros is crazy-talk. There is a time-honored pattern you use to fix this in the macro itself: wrap the macro with "do { } while (0)".
Re: How to properly use macros in C
#9 One strange phenomenon when coding in C is using macros. This is not something which can be seen in other programming languages (other than C++).
But again, Lisps generally have more powerful macros than C does - they allow for arbitrary compile-time computation.
Re: How to properly use macros in C
#10Calling all C preprocessor directives (like #include and #if) "macros" makes me skeptical. Is this usage common?
You are correct, this usage is wrong. They are "preprocessor directives", and macros are only what come after #define.