hollow swan
I am trying to add digits of a variable length number, and am using @addWithOverflow to detect carry out, though am unsure how to use the result as carry in for the next digit.
I would expect to find something like @adcWithOverflow(a: anytype, b: anytype, c: u1) though seemingly there isn't.
frail glen
conceptually, it does an addOverflow with a + b + c. So you can do the following and the compiler should figure it out:
addOverflowCarry(a, b, carry):
out, c1 = addOverflow(a, b)
out, c2 = addOverflow(out, carry)
return out, c1 or c2
Unfortunately, zig seems to have poor LLVM codegen here, even if clang/gcc figure it out: https://godbolt.org/z/6f3Ef3EK9