Release v1.1.1: Temporary fix for #56

eliaskosunen · Mar 16, 2022 · 72181aa · 72181aa
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diff --git a/CHANGELOG.md b/CHANGELOG.md
@@ -1,3 +1,21 @@
+# 1.1.1
+
+_Released 2022-03-16_
+
+ * Fix issue with values being skipped when using files and `file.sync()` (#56)
+   * Every call to `file.sync()` needs to be accompanied by a call to `reset_begin_iterator()` to the result object
+   * This is a temporary fix, permanent fix coming in v2.0.0
+
+```cpp
+int i;
+auto ret = scn::scan(scn::cstdin(), "{}", i);
+scn::cstdin().sync();
+ret.range().reset_begin_iterator();
+
+// Not necessary with input and prompt
+ret = scn::input("{}", i);
+```
+
 # 1.1
 
 _Released 2022-03-12_

diff --git a/include/scn/detail/file.h b/include/scn/detail/file.h
@@ -21,8 +21,8 @@
 #include <cstdio>
 #include <string>
 
-#include "range.h"
 #include "../util/algorithm.h"
+#include "range.h"
 
 namespace scn {
     SCN_BEGIN_NAMESPACE
@@ -260,6 +260,11 @@ namespace scn {
                 return !operator<(o);
             }
 
+            void reset_begin_iterator() const noexcept
+            {
+                m_current = 0;
+            }
+
         private:
             friend class basic_file;
 

diff --git a/include/scn/detail/range.h b/include/scn/detail/range.h
@@ -27,6 +27,38 @@ namespace scn {
     SCN_BEGIN_NAMESPACE
 
     namespace detail {
+        namespace _reset_begin_iterator {
+            struct fn {
+            private:
+                template <typename Iterator>
+                static auto
+                impl(Iterator& it, priority_tag<1>) noexcept(
+                    noexcept(it.reset_begin_iterator()))
+                    -> decltype(it.reset_begin_iterator())
+                {
+                    return it.reset_begin_iterator();
+                }
+
+                template <typename Iterator>
+                static void impl(Iterator&, size_t, priority_tag<0>) noexcept
+                {
+                }
+
+            public:
+                template <typename Iterator>
+                auto operator()(Iterator& it) const
+                    noexcept(noexcept(fn::impl(it, priority_tag<1>{})))
+                        -> decltype(fn::impl(it, priority_tag<1>{}))
+                {
+                    return fn::impl(it, priority_tag<1>{});
+                }
+            };
+        }  // namespace _reset_begin_iterator
+        namespace {
+            static constexpr auto& reset_begin_iterator =
+                static_const<detail::_reset_begin_iterator::fn>::value;
+        }
+
         template <typename Iterator, typename = void>
         struct extract_char_type;
         template <typename Iterator>
@@ -356,6 +388,10 @@ namespace scn {
                 m_read = 0;
             }
 
+            void reset_begin_iterator() {
+                detail::reset_begin_iterator(m_begin);
+            }
+
             /**
              * Construct a new source range from `begin()` and `end()`, and wrap
              * it in a new `range_wrapper`.

diff --git a/include/scn/scan/scan.h b/include/scn/scan/scan.h
@@ -279,6 +279,7 @@ namespace scn {
         auto& range = stdin_range<CharT>();
         auto ret = detail::scan_boilerplate(range, f, a...);
         range.sync();
+        ret.range().reset_begin_iterator();
         return ret;
     }
 #endif