import std.algorithm; struct Foo { int bar(string) { return 1; } void run() { auto result = map!(bar)(["test"]); } }
void main() { } D:\DMD\dmd2\windows\bin\..\..\src\phobos\std\algorithm.d(128): Error: this for bar needs to be type Foo not type Map!(bar,string[]) I can't use a virtual function as an alias parameter to a template, it either has to be a free function or a static function. So basically I have to use delegates: import std.algorithm; import std.traits; import std.stdio; auto myMap(Delegate, Range)(Delegate dg, Range t) { ReturnType!(dg)[] result; foreach (val; t) { result ~= dg(val); } return result; } struct Foo { int bar(string) { return 1; } void run() { auto result = myMap(&bar, ["test", "test"]); writeln(result); } } void main() { auto foo = Foo(); foo.run(); } But this means I have to take every Phobos function which I need and which takes an alias and convert it to a delegate version if I ever want to use it inside a struct or a class for non-static functions. Can't Phobos functions be made smarter so they work with virtual functions? Or would "alias" need re-engineering?