In the code below, x and y are implicitly converted to uint and ushort before the function preconditions are run.

Is there any way to change this behavior? It feels unintuitive and I can't find in the spec where it says when the conversions in this case occur, but it clearly happens before the preconditions are run.

import std.stdio: writeln;

void foo(uint x)
    in (x >= 0)
{
    writeln(x);
}

void foo(ushort x)
    in (x >= 0)
{
    writeln(x);
}

void main() {
    int x = -1;
    foo(x); //prints 4294967295
    short y = -1;
    foo(y); //prints 65535
}

On 5/24/22 4:46 PM, jmh530 wrote:

import std.stdio: writeln;

void foo(uint x)
     in (x >= 0)
{
     writeln(x);
}

void foo(ushort x)
     in (x >= 0)
{
     writeln(x);
}

void main() {
     int x = -1;
     foo(x); //prints 4294967295
     short y = -1;
     foo(y); //prints 65535
}

// e.g.
foo(int x)
in (x >= 0)
{
   return foo(uint(x));
}

And remove those useless in conditions on the unsigned versions, an unsigned variable is always >= 0.

-Steve

On Tuesday, 24 May 2022 at 21:05:00 UTC, Steven Schveighoffer wrote:

// e.g.
foo(int x)
in (x >= 0)
{
   return foo(uint(x));
}

Thanks. That makes perfect sense. I just got thrown by the preconditions not running first.