Exercises

Exercise 11-1. Write a generic min function for values that support <.

fn min(a: anytype, b: @TypeOf(a)) @TypeOf(a)

Return the smaller value.

Test it with:

• i32
• u64
• f64

Exercise 11-2. Write a generic swap function.

The function should exchange two values using pointers.

fn swap(a: anytype, b: anytype) void

Test it with integers and floating-point values.

Exercise 11-3. Write a generic max3 function.

fn max3(a: anytype, b: @TypeOf(a), c: @TypeOf(a)) @TypeOf(a)

Return the largest of three values.

Exercise 11-4. Modify this function so it accepts only integer types:

fn add(a: anytype, b: @TypeOf(a)) @TypeOf(a)

Use @typeInfo.

Print a compile-time error for unsupported types.

Exercise 11-5. Write a generic Point struct.

Example usage:

const IntPoint = Point(i32);

var p = IntPoint{
    .x = 10,
    .y = 20,
};

Add a method that prints the coordinates.

Exercise 11-6. Add a clear method to the generic Stack type.

The method should reset the length to zero without modifying stored elements.

Exercise 11-7. Write a generic fixed-size queue.

Requirements:

• compile-time element type
• compile-time capacity
• push
• pop
• isEmpty

Use a circular buffer.

Exercise 11-8. Write a generic counter wrapper.

The struct should:

• store a value
• track update count
• provide a method to assign a new value

Example:

var c = Counter(i32){
    .value = 0,
    .updates = 0,
};

Exercise 11-9. Write a generic function that accepts only floating-point types.

Use:

@typeInfo

Reject all other types with:

@compileError

Exercise 11-10. Write a function that accepts only pointers.

The function should print whether the pointer is null.

Exercise 11-11. Write a generic sum function for arrays.

Example:

const values = [_]i32{ 1, 2, 3, 4 };

Return the sum of all elements.

Exercise 11-12. Write a compile-time check requiring a declaration named init.

Use:

@hasDecl

Test it with:

• one valid type
• one invalid type

Exercise 11-13. Write a generic function that calls next() on its argument.

The function should fail at compile time if the declaration does not exist.

Exercise 11-14. Extend Exercise 11-13.

Require both:

• read
• write

Produce separate compile-time errors for each missing declaration.

Exercise 11-15. Implement a runtime-dispatched logger.

The logger should contain:

• an erased object pointer
• a function pointer for writing messages

Implement two backends:

• console logger
• memory logger

Exercise 11-16. Write two unrelated structs satisfying the same interface convention.

Both should provide:

process()

Write one generic function that calls the method.

Exercise 11-17. Write a generic function that prints type categories.

Possible outputs:

• integer
• float
• pointer
• struct
• other

Use @typeInfo.

Exercise 11-18. Write a generic function that distinguishes between signed and unsigned integers.

Hint:

.int.signedness

Exercise 11-19. Implement a small generic formatter.

Create a struct:

const Person = struct {
    name: []const u8,
    age: u8,
};

Write a formatting function that prints the fields.

Exercise 11-20. Write a compile-time debug flag.

Example:

fn log(comptime enabled: bool, message: []const u8) void

When enabled is false, no logging code should remain in the generated program.