scan more

test/scan.h

@@ -8,6 +8,7 @@
 #include <array>
 #include <cassert>
 #include <climits>
+#include <tuple>
 
 #include "fmt/format.h"
 
@@ -556,18 +557,22 @@ auto make_scan_args(T&... args) -> std::array<scan_arg, sizeof...(T)> {
   return {{args...}};
 }
 
-template <typename T> class scan_value {
+template <typename... T> class scan_data {
  private:
-  T value_;
+  std::tuple<T...> values_;
 
  public:
-  scan_value(T value) : value_(std::move(value)) {}
+  scan_data(T... values) : values_(std::move(values)...) {}
 
-  auto value() const -> const T& { return value_; }
+  auto value() const -> decltype(std::get<0>(values_)) {
+    return std::get<0>(values_);
+  }
 };
 
+class scan_error {};
+
 // A rudimentary version of std::expected for testing the API shape.
-template <typename T> class expected {
+template <typename T, typename E> class expected {
  private:
   T value_;
 
@@ -577,7 +582,8 @@ template <typename T> class expected {
   auto operator->() const -> const T* { return &value_; }
 };
 
-template <typename T> using scan_result = expected<scan_value<T>>;
+template <typename... T>
+using scan_result = expected<scan_data<T...>, scan_error>;
 
 void vscan(detail::scan_buffer& buf, string_view fmt, scan_args args) {
   auto h = detail::scan_handler(fmt, buf, args);
@@ -598,12 +604,12 @@ auto scan(string_view input, string_view fmt) -> scan_result<T> {
   static_assert(std::is_same<remove_cvref_t<T>, T>::value, "");
   auto value = T();
   scan_to(input, fmt, value);
-  return scan_value<T>(std::move(value));
+  return scan_data<T>(std::move(value));
 }
 
-template <typename InputRange, typename... T,
-          FMT_ENABLE_IF(!std::is_convertible<InputRange, string_view>::value)>
-auto scan_to(InputRange&& input, string_view fmt, T&... args)
+template <typename Range, typename... T,
+          FMT_ENABLE_IF(!std::is_convertible<Range, string_view>::value)>
+auto scan_to(Range&& input, string_view fmt, T&... args)
     -> decltype(std::begin(input)) {
   auto it = std::begin(input);
   vscan(get_buffer(it), fmt, make_scan_args(args...));