Kevin Bailey via Digitalmars-d-learn wrote:
How many times does the following loop print? I ran into this twice
doing the AoC exercises. It would be nice if it Just Worked.
```
import std.stdio;
int main()
{
char[] something = ['a', 'b', 'c'];
for (auto i = -1; i < something.length; ++i)
writeln("less than");
return 0;
}
```
Pretty nasty.
This seems to work but just looks bad to me. I would never write
code like this. It would also break if the array 'something' had
more than int.max elements.
```
import std.stdio;
int main()
{
char[] something = ['a', 'b', 'c'];
// len = 3, type ulong
writeln("len: ", something.length);
writeln("typeid(something.length): ", typeid(something.length));
// To make the loop execute, must cast something.length
// which is a ulong, to an int, which prevents i from
// being promoted from int to ulong and overflowing.
// The loop executes 4 times, when i is -1, 0, 1, and 2.
for (auto i = -1; i < cast(int)something.length; ++i) {
writeln("i: ", i);
}
return 0;
}
```
output:
len: 3
typeid(something.length): ulong
i: -1
i: 0
i: 1
i: 2
