On 23.06.2016 14:58, Steven Schveighoffer wrote:
On 6/21/16 5:19 PM, Timon Gehr wrote:
The problem here is that both variants make sense depending on context
and there is no syntax to distinguish between them. This proposal
interacts in a weird way with IFTI.
I know you are probably right, but can you explain maybe via an example
what you mean? I'm not understanding your point.
-Steve
One might legitimately want to pass a inout delegate to some inout
function and then use the delegate on data with arbitrary mutability
qualifiers, not just inout.
The IFTI comment was about for example something like this:
struct S{
void bar(inout int){}
void foo(T)(T arg)inout{
// this looks like it can be called with any argument
arg(&bar);
}
}
void main(){
immutable(S) s;
void delegate(void delegate(inout(int))) dg = x=>x(2);
s.foo(dg); // today, this works
// with the proposed semantics, IFTI deduces
// T = void delegate(void delegate(inout(int)))
// but then cannot convert dg to a T after
// inout resolution
}
But I don't feel strongly about which of the two variants it should be.
It's weird either way, as long as there can be only one inout in scope.
