How can I use a c++ template as an a parameter to an objective-c method? essentially I want to do something like this:
template<typename T>
- (void)method:(T)arg
but that doesn't work. according to this document this is possible however it does not provide any examples. Does anyone know how tot do this?
No you can't do that.
Objective-C classes, protocols, and categories cannot be declared inside a C++ template, nor can a C++ template be declared inside the scope of an Objective-C interface, protocol, or category.
Even if it is possible to declare that template, it is useless as Objective-C methods cannot be overloaded by type.
When the documentation says "C++ template parameters can also be used as receivers or parameters (though not as selectors) in Objective-C message expressions", that means that you can call an Objective-C method from within a templated C++ class or function, not that you can actually make a templated Objective-C method.
For example:
template<typename T>
void f(id obj, T t) {
[obj doSomethingWithObject:t];
}
...should work (although I haven't tested it). Of course, the type used when calling f would have to be something that could validly be passed as a parameter to doSomethingWithObject:, otherwise the calling code wouldn't compile.