Abstract base class as template parameter (for std::set comparator)

I'm creating std::set objects with my own comparators. My comparators
are in following hierarchy, rooted at the abstract base class
BaseCompare:

class BaseCompare
{
     virtual bool operator()(const SomeOtherClass &lhs, const
SomeOtherClass &rhs) const = 0;
};

class ACompare : BaseCompare
{
     bool operator()(const SomeOtherClass &lhs, const SomeOtherClass
&rhs) const
     {
         ...
     }
};

class BCompare : BaseCompare
{
     bool operator()(const SomeOtherClass &lhs, const SomeOtherClass
&rhs) const
     {
         ...
     }
};

I want to dynamically set what comparator is used when I create a
set. I want to be able to do something like this:

void something(BaseCompare &compareRef)
{
     std::set<SomeOtherClass, BaseCompare> aSet(compareRef);

     ...
}

Here I'd pass either an ACompare or a BCompare. Unfortunately, my
compiler complains about BaseCompare's virtual function. Is there a
way to fix this?

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