On 12/8/2014 3:14 PM, Dicebot wrote:
On Monday, 8 December 2014 at 21:12:47 UTC, Walter Bright wrote:
On 12/8/2014 12:54 PM, Dicebot wrote:
struct ByLine
{
scope string front();
// ...
}
auto byLine(File file)
{
return ByLine(file);
}
scope /* ref */ string foo(scope /* ref */ string input)
{
return input[1..$];
}
void main()
{
auto r = file.byLine.map!foo;
string s = r.front; // this should not compile
string s = r.front.dup; // this should compile
// how foo signature should look like for this to work?
}
front() should return a 'scope ref string'.
That seems to contradict your other statement:
A 'scope ref' parameter may not be returned as a 'ref' or a 'scope ref'.
Just make it a 'ref' parameter.
Please check `foo()` once more - it needs to accept scope (ref) to be able to
accept ByLine.front as an argument. And it also needs to pass it down the call
chain - but returning `input` by reference is illegal according to
abovementioned rule.
It can still be passed down as a 'ref' parameter.
