Initial range support in scan

Author: vitaut

test/scan-test.cc

@@ -76,7 +76,6 @@ TEST(scan_test, separator) {
   EXPECT_EQ(n2, 20);
 }
 
-#ifdef FMT_HAVE_STRPTIME
 struct num {
   int value;
 };
@@ -93,10 +92,9 @@ template <> struct scanner<num> {
   }
 
   template <class ScanContext>
-  auto scan(num&, ScanContext& ctx) const -> typename ScanContext::iterator {
-    // TODO
-    // return fmt::scan({ctx.begin(), ctx.end()}, "{}", n.value);
-    return ctx.begin();
+  auto scan(num& n, ScanContext& ctx) const -> typename ScanContext::iterator {
+    // TODO: handle specifier
+    return fmt::scan(ctx, "{}", n.value);
   }
 };
 }  // namespace fmt
@@ -105,9 +103,8 @@ TEST(scan_test, read_custom) {
   auto input = "42";
   auto n = num();
   fmt::scan(input, "{:}", n);
-  // EXPECT_EQ(n, 42);
+  EXPECT_EQ(n.value, 42);
 }
-#endif
 
 TEST(scan_test, invalid_format) {
   EXPECT_THROW_MSG(fmt::scan("", "{}"), fmt::format_error,

test/scan.h

@@ -94,6 +94,10 @@ class scan_buffer {
       value_ = *buf->ptr_;
     }
 
+    friend scan_buffer& get_buffer(iterator it) {
+      return *it.buf_;
+    }
+
    public:
     iterator() : ptr_(sentinel()), buf_(nullptr) {}
 
@@ -154,7 +158,7 @@ class string_scan_buffer : public scan_buffer {
 #ifdef _WIN32
 void flockfile(FILE* f) { _lock_file(f); }
 void funlockfile(FILE* f) { _unlock_file(f); }
-int getc_unlocked(FILE *f) { return _fgetc_nolock(f); }
+int getc_unlocked(FILE* f) { return _fgetc_nolock(f); }
 #endif
 
 // A FILE wrapper. F is FILE defined as a template parameter to make
@@ -534,6 +538,15 @@ auto scan(string_view input, string_view fmt, T&... args)
   return input.begin() + (buf.begin().base() - input.data());
 }
 
+template <typename InputRange, typename... T,
+          FMT_ENABLE_IF(!std::is_convertible<InputRange, string_view>::value)>
+auto scan(InputRange&& input, string_view fmt, T&... args)
+    -> decltype(std::begin(input)) {
+  auto it = std::begin(input);
+  vscan(get_buffer(it), fmt, make_scan_args(args...));
+  return it;
+}
+
 template <typename... T> bool scan(std::FILE* f, string_view fmt, T&... args) {
   auto&& buf = detail::file_scan_buffer(f);
   vscan(buf, fmt, make_scan_args(args...));