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//
// One of the more common uses of 'comptime' function parameters is
// passing a type to a function:
//
// fn foo(comptime MyType: type) void { ... }
//
// In fact, types are ONLY available at compile time, so the
// 'comptime' keyword is required here.
//
// Please take a moment to put on the wizard hat which has been
// provided for you. We're about to use this ability to implement
// a generic function.
//
const print = @import("std").debug.print;
pub fn main() void {
// Here we declare arrays of three different types and sizes
// at compile time from a function call. Neat!
const s1 = makeSequence(u8, 3); // creates a [3]u8
const s2 = makeSequence(u32, 5); // creates a [5]u32
const s3 = makeSequence(i64, 7); // creates a [7]i64
print("s1={any}, s2={any}, s3={any}\n", .{ s1, s2, s3 });
}
// This function is pretty wild because it executes at runtime
// and is part of the final compiled program. The function is
// compiled with unchanging data sizes and types.
//
// And yet it ALSO allows for different sizes and types. This
// seems paradoxical. How could both things be true?
//
// To accomplish this, the Zig compiler actually generates a
// separate copy of the function for every size/type combination!
// So in this case, three different functions will be generated
// for you, each with machine code that handles that specific
// data size and type.
//
// Please fix this function so that the 'size' parameter:
//
// 1) Is guaranteed to be known at compile time.
// 2) Sets the size of the array of type T (which is the
// sequence we're creating and returning).
//
fn makeSequence(comptime T: type, ??? size: usize) [???]T {
var sequence: [???]T = undefined;
var i: usize = 0;
while (i < size) : (i += 1) {
sequence[i] = @intCast(T, i) + 1;
}
return sequence;
}
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