Bug 6197 – std.traits.isImplicitlyConvertible returns some wrong results.
Status
RESOLVED
Resolution
FIXED
Severity
normal
Priority
P2
Component
phobos
Product
D
Version
D2
Platform
All
OS
All
Creation time
2011-06-23T04:01:00Z
Last change time
2012-06-14T02:20:55Z
Assigned to
nobody
Creator
k.hara.pg
Comments
Comment #0 by k.hara.pg — 2011-06-23T04:01:22Z
pragma(msg, implicitlyConverts!(const(uint), ubyte));
should print 'false', but 'true'.
Cause of this bug:
Current implementation is here:
template isImplicitlyConvertible(From, To)
{
enum bool isImplicitlyConvertible = is(typeof({
void fun(To) {}
From v;
fun(f);
}()));
}
When From=const(uint) and To=ubyte, it is rewites as
enum bool isImplicitlyConvertible = is(typeof({
void fun(ubyte) {}
const(uint) v;
fun(f);
}()));
and function argument v is *optimized* to its initial value 0u and matches to parameter type ubyte by literal conversion.
How to fix:
The variables its initializers are not visible does not cause optimization.
So rewrite as:
enum bool isImplicitlyConvertible = is(typeof({
void fun(ref From v){
void gun(To) {}
gun(v);
}
}()));
Comment #1 by k.hara.pg — 2011-06-23T04:06:35Z
(In reply to comment #0)
> pragma(msg, implicitlyConverts!(const(uint), ubyte));
Sorry, this is miss type. Following is correct.
pragma(msg, isImplicitlyConvertible!(const(uint), ubyte));
Comment #2 by lovelydear — 2012-04-24T11:36:13Z
With 2.059 Win32
PS E:\DigitalMars\dmd2\samples> dmd -c bug.d
false