c++ - std::priority_queue: Custom ordering without defining comparator class -

i want have priority queue custom ordering, lazy am, don't want define comparator class implementing operator().

i compile:

std::priority_queue<int, std::vector<int>,      boost::bind(some_function, _1, _2, obj1, obj2)> queue; 

where some_function bool returning function taking 4 arguments, first , second being ints of queue, , 2 last ones objects needed calculating ordering (const references).

(error: ‘boost::bind’ cannot appear in constant-expression)

but doesn't compile. more simple

std::priority_queue<int, std::vector<int>, &compare> queue; 

won't compile, compare being binary function returning bool.

(error: type/value mismatch @ argument 3 in template parameter list ‘template class std::priority_queue’; expected type, got ‘compare’)

any suggestions?

this work:

std::priority_queue<int, std::vector<int>,      boost::function<bool(int,int)> > 

then pass in bind expression queue's constructor.

p.s. you're getting compilation errors because you're putting runtime-evaluated expressions typename or constant expression expected.