C Library - <assert.h>
The assert.h header file of the C Standard Library provides a macro called assert which can be used to verify assumptions made by the program and print a diagnostic message if this assumption is false.
The defined macro assert refers to another macro NDEBUG which is not part of <assert.h>. If NDEBUG is defined as a macro name at the point in the source file where <assert.h> is included , the assert macro is defined as follows:
#define assert(ignore) ((void)0)
Following is the only function defined in the header assert.h:
|S.N.||Function & Description|
|1||void assert(int expression)|
This is actually a macro and not a function, which can be used to add diagnostics in your C program.