Physicians may soon have a new way to help predict cancer at earlier stages. Interestingly, it may hinge on sodium levels. In a recent study, hyponatremia was associated with the subsequent diagnosis ...
Hyponatremia is a condition that happens when you don’t have enough sodium in your blood. We often try to limit how much salt (sodium) is in the foods we eat, but it’s important to remember that our ... What is the point of #define in C++? I've only seen examples where it's used in place of a "magic number" but I don't see the point in just giving that value to a variable instead.
define hyponatremia, c++ - Why use #define instead of a variable - Stack Overflow The #define directive is a preprocessor directive; the preprocessor replaces those macros by their body before the compiler even sees it. Think of it as an automatic search and replace of your source code. A const variable declaration declares an actual variable in the language, which you can use... well, like a real variable: take its address, pass it around, use it, cast/convert it, etc. Oh ...
define hyponatremia, The question is if users can define new macros in a macro, not if they can use macros in macros. As far as I know, what you're trying to do (use if statement and then return a value from a macro) isn't possible in ISO C... but it is somewhat possible with statement expressions (GNU extension). Since #define s are essentially just fancy text find-and-replace, you have to be really careful about how they're expanded. I've found that this works on gcc and clang by default: I know that this is a long time after the original query, but this may still be useful. This can be done in GCC using the stringify operator "#", but it requires two additional stages to be defined first.
#define XSTR(x) STR(x) #define STR(x) #x The value of a macro can then be displayed with: #pragma message "The value of ABC: " XSTR(ABC) See: 3.4 Stringification in the gcc online ...
