digitalmars.D.bugs - [Issue 10709] New: reduce 1-function + no seed, wrong type inference
- d-bugmail puremagic.com (47/47) Jul 23 2013 http://d.puremagic.com/issues/show_bug.cgi?id=10709
http://d.puremagic.com/issues/show_bug.cgi?id=10709 Summary: reduce 1-function + no seed, wrong type inference Product: D Version: D2 Platform: All OS/Version: All Status: NEW Keywords: rejects-valid Severity: normal Priority: P2 Component: Phobos AssignedTo: monarchdodra gmail.com ReportedBy: monarchdodra gmail.com When reduce is not given a seed, it takes the ranges "front" as a first element, however, seed's type should be that of the result of calling "fun". This is relevent for a function for example, that takes int, and returns a double, or a function that takes operates on const(char)[], and is passed a string: In both case, reduce will error out when trying to store the result (eg double) into the seed (eg int). What is interesting is that "reduce!fun" gets it wrong, but "reduce!(fun, fun...)" gets it right. //---- import std.stdio, std.algorithm; void main(string[] args) { { enum foo = "a + 0.5 * b"; auto r = [0, 1, 2, 3]; //auto r1 = reduce!foo(r); //<-- HERE auto r2 = reduce!(foo, foo,)(r); //writeln(r1); writeln(r2); } { const(char)[] foo(const(char)[], const(char)[]); string[] r = ["hello", "world"]; //auto r1 = reduce!foo(r); //<-- HERE auto r2 = reduce!(foo, foo,)(r); //writeln(r1); writeln(r2); } } //---- -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Jul 23 2013