hidden basin
I thought I could write code to determine these sizes, but the following does not work. The reported size is zero. Is there another way I can do this?
const std = @import("std");
const expectEqual = std.testing.expectEqual;
test "comptime sizes" {
const i = 7;
try expectEqual(comptime_int, @TypeOf(i));
// try expectEqual(8, @sizeOf(@TypeOf(i))); // fails
const f = 3.14;
try expectEqual(comptime_float, @TypeOf(f));
// try expectEqual(8, @sizeOf(@TypeOf(f))); // fails
}
brisk seal
the size is zero and that is correct
no runtime size
why do you even expect it to be 8?
hidden basin
Is that because the value gets embedded into the generate code?
hidden basin
Can you explain that more? What is "rodata"?
brisk seal
what did you mean by embedded into the generated code
if you know how assembly works / what a binary file is, .rodata is a label for the read only data section in the final binary/executable/object file
hidden basin
Okay, I didn't know about that. Thanks!
What if I had an array of comptime_int values? Wouldn't that have a non-zero size?
brisk seal
look man, its not gonna show up in your final binary so the concept of size doesnt really make sense
it only takes up space in the compilers memory. not in your binaries
hidden basin
Interesting! Is it fair to say the comptime_int and comptime_float values are inlined in the generated code? For example, if I write a program that reads numbers from a file, iterates over them, and prints the result of multiplying each number by some comptime_int value then it seems the comptime_int value must be known at run-time. I'm trying to learn what happens to that value in the generated code.