Macro acts more like scripts. Macro #define A bbb replace A with bbb in the code.
#define oldmax(x, y) ((x)>(y)?(x):(y))q = oldmax(abc, 123);
After the preprocessor goes through the code, it will look like this:
q = ((abc)>(123)?(abc):(123));Macro operators
##
The ## operator takes two separate tokens and pastes them together to form a single token.
Following macro can be used to initialize the variables in the beginning.
(Note you can use \to type in new line.)
#define INITIALIZATION(type, varname, value) \
type orig_##varname = value;After declaration, we can use it like the follows:
#include <string>
INITIALIZATION( std::string, name, “Cindy” );
INITIALIZATION( float, weight, 55.0f );
INITIALIZATION( float, height, 166.0f );Test for output:
std::cout <<"orig_name = " << orig_name <<endl;
std::cout <<"orig_weight = " << orig_weight <<endl;
std::cout <<"orig_height = " << orig_height <<endl;
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