low shard
I tried this:
pub fn toString(self: Vector4) []const u8 {
var buffer: [2048]u8 = undefined;
const str = try std.fmt.bufPrint(&buffer, "{}, {}, {}, {}", .{ self.x, self.y, self.z, self.w });
return str;
}
But apparently I'm returning a pointer that no longer exists after returning, so it always gives me an error. What are my alternatives?
jaunty wolf
Accept a writer or allocator into your function
low shard
Should I use allocPrint then?
stuck geode
If you accept an allocator, then you'd use std.fmt.allocPrint. If you accept a buffer, than you'd use what you're using, if you accept a writer, then you'd use std.fmt.format.
low shard
I'm using allocPrint now
My test don't pass tho
pub fn toString(self: Vector4, allocator: std.mem.Allocator) ![]const u8 {
return std.fmt.allocPrint(allocator, "{}, {}, {}, {}", .{ self.x, self.y, self.z, self.w });
}
yikes, hang on
Doesn't give me the error anymore
But test don't pass
stuck geode
FYI: Zig has these magic methods that are poorly documented.
One is "format". If you do:
pub fn format(self: Vector4, comptime _: []const u8, _: std.fmt.FormatOptions, out: anytype) !void {
return std.fmt.format(out, "{} {} {} {}", .{self.x, self.y, self.z, self.w});
}
Then you'd be able to use the vector4 as an format argument directly.
(which would mean that the user of your library would then have the flexibility to stringify a vector using a writer, or a buffer, or an allocator)
Hard to tell why they don't pass, maybe use the verbosely named testing.expectEqualStrings to get an more useful printout of actual vs expected.
final cipher