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@@ -25,3 +25,65 @@ private:
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It begin_, end_;
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};
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}
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+
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+namespace stream {
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+/**
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+ * Construct a stream out of the given container. If C && is an rvalue
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+ * reference, the returned object will take ownership of cont. Otherwise, we
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+ * capture cont by reference to maximise performance.
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+ */
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+template <typename C>
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+auto of(C && cont) -> detail::stream_base<decltype(*cont.begin())> {
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+ return std::make_shared<detail::source_stream<C>>(std::forward<C>(cont));
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+}
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+
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+template <typename T> detail::stream_base<T &> empty() {
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+ return std::make_shared<detail::range_stream<T *>>(nullptr, nullptr);
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+}
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+
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+/**
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+ * Construct a single element stream containing the pointer given
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+ */
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+template <typename T> detail::stream_base<T &> of(T * ptr) {
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+ return std::make_shared<detail::range_stream<T *>>(ptr, ptr + 1);
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+}
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+
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+/**
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+ * Construct a stream from input iterators representing the start and end
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+ * Requirements: It must be an iterator type that provides the trait
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+ * 'reference'
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+ */
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+template <typename It>
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+detail::stream_base<typename It::reference> of(It begin, It end) {
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+ return std::make_shared<detail::range_stream<It>>(begin, end);
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+}
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+
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+/**
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+ * Construct a stream given certain start and end bounds.
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+ * e.g. stream::make_range_stream(0, 10)
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+ */
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+template <typename T> detail::stream_base<T &> range(T start, T const & end) {
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+ std::vector<T> vec;
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+ vec.reserve(end - start);
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+ while (start < end) {
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+ vec.emplace_back(start++);
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+ }
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+ return make_stream(std::move(vec));
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+}
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+
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+/**
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+ * Construct a stream given certain start and end bounds, as well as an
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+ * increment amount. e.g. stream::make_range_stream(0, 10, 2)
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+ */
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+template <typename T>
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+detail::stream_base<T &> range(T start, T const & end, T const & increment) {
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+ int elems{(end - start) / increment};
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+ if (elems < 0 || end == start) { return {}; }
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+ std::vector<T> vec{start};
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+ vec.reserve(elems + 1);
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+ while (elems-- > 0) {
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+ vec.emplace_back(start += increment);
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+ }
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+ return make_stream(std::move(vec));
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+}
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+}
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Sam Jaffe