C++ concepts: BinaryPredicate
BinaryPredicate is a set of requirements expected by some of the standard library facilities from the user-provided arguments.
bin_pred and a pair of iterators
iter2 or an iterator
iter and a value
value, the expression bin_pred(*iter1, *iter2) or, respectively, bin_pred(*iter, value), must be contextually convertible to bool.
In addition, evaluation of that expression is not allowed to call non-const member functions of the dereferenced iterators.
The following standard library facilities expect a
BinaryPredicate which isn't a