Add istream example

Author: patrickroberts

examples/CMakeLists.txt

@@ -1,7 +1,16 @@
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
-function(beman_add_example)
-    beman_add_executable(${ARGN} CATEGORY examples)
+function(beman_add_examples)
+    foreach(name ${ARGN})
+        beman_add_executable(
+                TARGET ${name}
+                SOURCES ${name}.cpp
+                CATEGORY examples
+        )
+    endforeach()
 endfunction()
 
-beman_add_example(TARGET sum_views)
+beman_add_examples(
+    istream
+    sum_views
+)

examples/istream.cpp

@@ -0,0 +1,21 @@
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+
+#include <beman/any_view/any_view.hpp>
+
+#include <algorithm>
+#include <iostream>
+#include <sstream>
+#include <ranges>
+
+namespace bav = beman::any_view;
+
+int main() {
+    std::istringstream         in{"1 2 3 4"};
+    bav::any_view<const int>   view{std::views::istream<int>(in)};
+    std::ostream_iterator<int> out{std::cout, ", "};
+
+    std::ranges::copy(view, out);
+    std::cout << std::endl;
+
+    return 0;
+}

examples/sum_views.cpp

@@ -7,7 +7,6 @@
 #include <vector>
 
 namespace bav = beman::any_view;
-using opt     = bav::any_view_options;
 
 auto sum(bav::any_view<const int> v1, bav::any_view<const int> v2) {
     auto result = 0;

include/beman/any_view/detail/iterator_adaptor.hpp

@@ -37,6 +37,14 @@ class iterator_adaptor final : public iterator_interface<ElementT, RefT, RValueR
     }
 
   public:
+    constexpr iterator_adaptor() noexcept(std::is_nothrow_default_constructible_v<IteratorT> and
+                                          std::is_nothrow_default_constructible_v<SentinelT>) = default;
+
+    constexpr iterator_adaptor(const iterator_adaptor&) = default;
+
+    constexpr iterator_adaptor(iterator_adaptor&&) noexcept(std::is_nothrow_move_constructible_v<IteratorT> and
+                                                            std::is_nothrow_move_constructible_v<SentinelT>) = default;
+
     constexpr iterator_adaptor(IteratorT&& iterator, SentinelT&& sentinel) noexcept(get_noexcept())
         : iterator(std::move(iterator)), sentinel(std::move(sentinel)) {}