How to create a neat cast?

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1

My code is:

const expect = @import("std").testing.expect;

var a: i8 = 127;
var b: i8 = 1;

test "test1" {
    try expect(@as(i64, a + b) == 128);
}

test "test2" {
    try expect(@as(i64, a) + @as(i64, b) == 128);
}
  • Description: if i sum a and b then cast in “test1”, it will have a overflow panic. So i have to cast one by one to sum in “test2”.
  • Question: This method is quite lengthy, is there a way to make it simpler? Thanks
2

You probably already know this, but the only way I know of to simplify it is to use a larger type, for example, i16, instead of i8 for a and b, since the sum of 128 and 1 cannot be represented in an i8. Zig is very strict about type conversions and requires them to be explicit.

Edit: even using u8 would be sufficient.

1 Like
3

Yeah l thought about that, but i still hope another way that don’t need to change type of unnecessary variables.

4

It looks like if you cast the first value, the second one is coerced safely to the same type:

    try expect(@as(i16, a) + b == 128);

This worked for me with version 0.10.0-dev.4217+9d8cdb855.

1 Like
5

that’s it!!! also with zig 0.9.1