import quincy beta 17.1.0

[ceph.git] / ceph / src / boost / libs / stl_interfaces / example / repeated_chars_iterator.cpp

diff --git a/ceph/src/boost/libs/stl_interfaces/example/repeated_chars_iterator.cpp b/ceph/src/boost/libs/stl_interfaces/example/repeated_chars_iterator.cpp
new file mode 100644 (file)
index 0000000..83a158b
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+++ b/ceph/src/boost/libs/stl_interfaces/example/repeated_chars_iterator.cpp
@@ -0,0 +1,60 @@
+// Copyright (C) 2019 T. Zachary Laine
+//
+// Distributed under the Boost Software License, Version 1.0. (See
+// accompanying file LICENSE_1_0.txt or copy at
+// http://www.boost.org/LICENSE_1_0.txt)
+#include <boost/stl_interfaces/iterator_interface.hpp>
+
+#include <string>
+
+#include <cassert>
+
+
+//[ repeated_chars_iterator
+struct repeated_chars_iterator : boost::stl_interfaces::iterator_interface<
+                                     repeated_chars_iterator,
+                                     std::random_access_iterator_tag,
+                                     char,
+                                     char>
+{
+    constexpr repeated_chars_iterator() noexcept :
+        first_(nullptr),
+        size_(0),
+        n_(0)
+    {}
+    constexpr repeated_chars_iterator(
+        char const * first, difference_type size, difference_type n) noexcept :
+        first_(first),
+        size_(size),
+        n_(n)
+    {}
+
+    constexpr char operator*() const noexcept { return first_[n_ % size_]; }
+    constexpr repeated_chars_iterator & operator+=(std::ptrdiff_t i) noexcept
+    {
+        n_ += i;
+        return *this;
+    }
+    constexpr auto operator-(repeated_chars_iterator other) const noexcept
+    {
+        return n_ - other.n_;
+    }
+
+private:
+    char const * first_;
+    difference_type size_;
+    difference_type n_;
+};
+//]
+
+
+int main()
+{
+    //[ repeated_chars_iterator_usage
+    repeated_chars_iterator first("foo", 3, 0); // 3 is the length of "foo", 0 is this iterator's position.
+    repeated_chars_iterator last("foo", 3, 7);  // Same as above, but now the iterator's position is 7.
+    std::string result;
+    std::copy(first, last, std::back_inserter(result));
+    assert(result == "foofoof");
+    //]
+}