On Wednesday, 9 March 2016 at 01:27:41 UTC, Dicebot wrote:
Looks like regression to me.
If SomeStruct contains indirections, it should be able to
deduce T as
const(SomeStruct).
It SomeStruct is strict value type, deducing T as both
SomeStruct and const(SomeStruct) would be fine.
But the behavior with 2.068 was bug-prone.
struct S
{
int value;
}
auto foo(T)(T start, T end)
{
pragma(msg, "In foo, T = ", T);
}
void main()
{
const S cs;
S ms;
foo(cs, ms); // [a] NG with 2.069.2, but T == S with 2.068!
foo(ms, cs); // [b] NG with 2.069.2, but T == const(S)
with 2.068!!
}
The both cases are disabled in the bugfix PR:
https://github.com/D-Programming-Language/dmd/pull/4818
I think that T should be deduced to the typeof(true ? cs : ms) at
line [a] and typeof(true ? ms : cs) at line [b], then the two
lines will get consistent deduction result T == const(S).
Kenji Hara
