Method operator ()

code/data-structures/heap.cpp:5–6

struct default_int_cmp {
  default_int_cmp() { }
  bool operator ()(const int &a, const int &b) const {
    return a < b; } };
template <class Compare = default_int_cmp> struct heap {
  int len, count, *q, *loc, tmp;
  Compare _cmp;