Cleanup iterator handling

fmtlib · Jan 11, 2024 · e5e94fe · e5e94fe
1 parent c534053
commit e5e94fe
Showing 1 changed file with 20 additions and 18 deletions.
diff --git a/include/fmt/format.h b/include/fmt/format.h
@@ -515,7 +515,21 @@ FMT_INLINE void assume(bool condition) {
 #endif
 }
 
-template <typename Char, typename InputIt, typename OutputIt>
+template <typename Char, typename InputIt>
+auto copy_str(InputIt begin, InputIt end, appender out) -> appender {
+  get_container(out).append(begin, end);
+  return out;
+}
+
+template <typename Char, typename InputIt, typename OutputIt,
+          FMT_ENABLE_IF(is_back_insert_iterator<OutputIt>::value)>
+auto copy_str(InputIt begin, InputIt end, OutputIt out) -> OutputIt {
+  get_container(out).append(begin, end);
+  return out;
+}
+
+template <typename Char, typename InputIt, typename OutputIt,
+          FMT_ENABLE_IF(!is_back_insert_iterator<OutputIt>::value)>
 FMT_CONSTEXPR auto copy_str(InputIt begin, InputIt end, OutputIt out)
     -> OutputIt {
   while (begin != end) *out++ = static_cast<Char>(*begin++);
@@ -532,19 +546,6 @@ FMT_CONSTEXPR auto copy_str(T* begin, T* end, U* out) -> U* {
   return out + size;
 }
 
-template <typename Char, typename InputIt>
-auto copy_str(InputIt begin, InputIt end, appender out) -> appender {
-  get_container(out).append(begin, end);
-  return out;
-}
-template <typename Char, typename InputIt>
-auto copy_str(InputIt begin, InputIt end,
-              std::back_insert_iterator<std::string> out)
-    -> std::back_insert_iterator<std::string> {
-  get_container(out).append(begin, end);
-  return out;
-}
-
 template <typename Char, typename R, typename OutputIt>
 FMT_CONSTEXPR auto copy_str(R&& rng, OutputIt out) -> OutputIt {
   return detail::copy_str<Char>(rng.begin(), rng.end(), out);
@@ -567,14 +568,15 @@ inline auto get_data(Container& c) -> typename Container::value_type* {
 
 // Attempts to reserve space for n extra characters in the output range.
 // Returns a pointer to the reserved range or a reference to it.
-template <typename Container, FMT_ENABLE_IF(is_contiguous<Container>::value)>
+template <typename OutputIt,
+          FMT_ENABLE_IF(is_back_insert_iterator<OutputIt>::value&&
+                            is_contiguous<typename OutputIt::container>::value)>
 #if FMT_CLANG_VERSION >= 307 && !FMT_ICC_VERSION
 __attribute__((no_sanitize("undefined")))
 #endif
 inline auto
-reserve(std::back_insert_iterator<Container> it, size_t n) ->
-    typename Container::value_type* {
-  Container& c = get_container(it);
+reserve(OutputIt it, size_t n) -> typename OutputIt::value_type* {
+  auto& c = get_container(it);
   size_t size = c.size();
   c.resize(size + n);
   return get_data(c) + size;