From cf0920de31e9b5f3c5ba6de19a1b4c8d0c58b907 Mon Sep 17 00:00:00 2001 From: Dave Gauer Date: Mon, 8 Feb 2021 20:35:28 -0500 Subject: Added Ex. 38-43 for pointers, updated README Added topics beyond the language basics from ziglearn.org to the README. That's a lot of exercises. I'd like to keep it under 100, though! --- 40_pointers2.zig | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) create mode 100644 40_pointers2.zig (limited to '40_pointers2.zig') diff --git a/40_pointers2.zig b/40_pointers2.zig new file mode 100644 index 0000000..b046dc1 --- /dev/null +++ b/40_pointers2.zig @@ -0,0 +1,27 @@ +// +// It's important to note that variable pointers and constant pointers +// are different types. +// +// Given: +// +// var foo: u8 = 5; +// const bar: u8 = 5; +// +// Then: +// +// &foo is of type "*u8" +// &bar is of type "*const u8" +// +// You can always make a constant pointer to a variable, but you cannot +// make a variable pointer to a constant. This sounds like a logic puzzle, +// but it just means that once data is declared immutable, you can't +// coerce it to a mutable type. It's a safety thing (to prevent mistakes). +// +const std = @import("std"); + +pub fn main() void { + const a: u8 = 12; + const b: *u8 = &a; // fix this! + + std.debug.print("a: {}, b: {}\n", .{a, b.*}); +} -- cgit v1.2.3-ZIG