| [section:count count] |
| |
| [heading Prototype] |
| |
| `` |
| template<class SinglePassRange, class Value> |
| typename range_difference<SinglePassRange>::type |
| count(SinglePassRange& rng, const Value& val); |
| |
| template<class SinglePassRange, class Value> |
| typename range_difference<const SinglePassRange>::type |
| count(const SinglePassRange& rng, const Value& val); |
| `` |
| |
| [heading Description] |
| |
| `count` returns the number of elements `x` in `rng` where `x == val` is `true`. |
| |
| [heading Definition] |
| |
| Defined in the header file `boost/range/algorithm/count.hpp` |
| |
| [heading Requirements] |
| |
| * `SinglePassRange` is a model of the __single_pass_range__ Concept. |
| * `Value` is a model of the `EqualityComparableConcept`. |
| * `SinglePassRange`'s value type is a model of the `EqualityComparableConcept`. |
| * An object of `SinglePassRange`'s value type can be compared for equality with an object of type `Value`. |
| |
| [heading Complexity] |
| |
| Linear. Exactly `distance(rng)` comparisons. |
| |
| [endsect] |
| |
| |
