C
Summary - Modern C
Combine _Generic, _Static_assert and atomics to write a type-safe macro.
Summary - Modern C combined
In this lesson you'll combine _Generic, _Static_assert and atomics to write a type-safe macro. The safe_print macro uses _Generic to select the type, _Static_assert to verify int size, and an atomic_int counter to track calls.
Together these three features show the power of modern C: compile-time safety, type-based selection and thread-safe counting. You'll merge solutions from previous lessons into one program. The program prints the type name on each call and increments the counter; finally it prints the counter value.
Exercise Write the safe_print macro
Add #include <stdatomic.h>. Write _Static_assert(sizeof(int) >= 4, "int en az 4 bayt");. Declare static atomic_int call_count = 0;. Write #define safe_print(x): select the type with _Generic((x), int: "int", double: "double", default: "diğer"), print via printf("%s\n", ...), then increment with atomic_fetch_add(&call_count, 1). In int main(void) call safe_print(42) and safe_print(3.14), finally print printf("%d\n", call_count).
Show example solution
#include <stdio.h>
#include <stdatomic.h>
_Static_assert(sizeof(int) >= 4, "int en az 4 bayt");
static atomic_int call_count = 0;
#define safe_print(x) printf("%s\n", _Generic((x), int: "int", double: "double", default: "diğer")); atomic_fetch_add(&call_count, 1)
int main(void) {
safe_print(42);
safe_print(3.14);
printf("%d\n", call_count);
return 0;
}
Test yourself
-
Which three features does safe_print combine?
- malloc, free, realloc
- _Generic, _Static_assert, atomics
- printf, scanf, fprintf
- fork, exec, wait
Show answer
_Generic, _Static_assert, atomics — safe_print combines _Generic + _Static_assert + atomics.
-
Complete the atomic increment call
static atomic_int call_count = 0;
____(&call_count, 1);
Show answer
static atomic_int call_count = 0;
atomic_fetch_add(&call_count, 1);
-
Match feature to role
- _Generic
- Type selection
- _Static_assert
- Compile check
- atomic_int
- Atomic counter
- printf
- Output writing
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