Move detail::truncating_iterator to fmt/compile.h

include/fmt/compile.h

@@ -25,6 +25,85 @@
 FMT_BEGIN_NAMESPACE
 namespace detail {
 
+template <typename OutputIt> class truncating_iterator_base {
+ protected:
+  OutputIt out_;
+  size_t limit_;
+  size_t count_ = 0;
+
+  truncating_iterator_base() : out_(), limit_(0) {}
+
+  truncating_iterator_base(OutputIt out, size_t limit)
+      : out_(out), limit_(limit) {}
+
+ public:
+  using iterator_category = std::output_iterator_tag;
+  using value_type = typename std::iterator_traits<OutputIt>::value_type;
+  using difference_type = std::ptrdiff_t;
+  using pointer = void;
+  using reference = void;
+  using _Unchecked_type =
+      truncating_iterator_base;  // Mark iterator as checked.
+
+  OutputIt base() const { return out_; }
+  size_t count() const { return count_; }
+};
+
+// An output iterator that truncates the output and counts the number of objects
+// written to it.
+template <typename OutputIt,
+          typename Enable = typename std::is_void<
+              typename std::iterator_traits<OutputIt>::value_type>::type>
+class truncating_iterator;
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::false_type>
+    : public truncating_iterator_base<OutputIt> {
+  mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_;
+
+ public:
+  using value_type = typename truncating_iterator_base<OutputIt>::value_type;
+
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  truncating_iterator& operator++() {
+    if (this->count_++ < this->limit_) ++this->out_;
+    return *this;
+  }
+
+  truncating_iterator operator++(int) {
+    auto it = *this;
+    ++*this;
+    return it;
+  }
+
+  value_type& operator*() const {
+    return this->count_ < this->limit_ ? *this->out_ : blackhole_;
+  }
+};
+
+template <typename OutputIt>
+class truncating_iterator<OutputIt, std::true_type>
+    : public truncating_iterator_base<OutputIt> {
+ public:
+  truncating_iterator() = default;
+
+  truncating_iterator(OutputIt out, size_t limit)
+      : truncating_iterator_base<OutputIt>(out, limit) {}
+
+  template <typename T> truncating_iterator& operator=(T val) {
+    if (this->count_++ < this->limit_) *this->out_++ = val;
+    return *this;
+  }
+
+  truncating_iterator& operator++() { return *this; }
+  truncating_iterator& operator++(int) { return *this; }
+  truncating_iterator& operator*() { return *this; }
+};
+
 // A compile-time string which is compiled into fast formatting code.
 class compiled_string {};
 

include/fmt/format.h

@@ -465,85 +465,6 @@ class counting_iterator {
   value_type operator*() const { return {}; }
 };
 
-template <typename OutputIt> class truncating_iterator_base {
- protected:
-  OutputIt out_;
-  size_t limit_;
-  size_t count_ = 0;
-
-  truncating_iterator_base() : out_(), limit_(0) {}
-  
-  truncating_iterator_base(OutputIt out, size_t limit)
-      : out_(out), limit_(limit) {}
-
- public:
-  using iterator_category = std::output_iterator_tag;
-  using value_type = typename std::iterator_traits<OutputIt>::value_type;
-  using difference_type = std::ptrdiff_t;
-  using pointer = void;
-  using reference = void;
-  using _Unchecked_type =
-      truncating_iterator_base;  // Mark iterator as checked.
-
-  OutputIt base() const { return out_; }
-  size_t count() const { return count_; }
-};
-
-// An output iterator that truncates the output and counts the number of objects
-// written to it.
-template <typename OutputIt,
-          typename Enable = typename std::is_void<
-              typename std::iterator_traits<OutputIt>::value_type>::type>
-class truncating_iterator;
-
-template <typename OutputIt>
-class truncating_iterator<OutputIt, std::false_type>
-    : public truncating_iterator_base<OutputIt> {
-  mutable typename truncating_iterator_base<OutputIt>::value_type blackhole_;
-
- public:
-  using value_type = typename truncating_iterator_base<OutputIt>::value_type;
-
-  truncating_iterator() = default;
-  
-  truncating_iterator(OutputIt out, size_t limit)
-      : truncating_iterator_base<OutputIt>(out, limit) {}
-
-  truncating_iterator& operator++() {
-    if (this->count_++ < this->limit_) ++this->out_;
-    return *this;
-  }
-
-  truncating_iterator operator++(int) {
-    auto it = *this;
-    ++*this;
-    return it;
-  }
-
-  value_type& operator*() const {
-    return this->count_ < this->limit_ ? *this->out_ : blackhole_;
-  }
-};
-
-template <typename OutputIt>
-class truncating_iterator<OutputIt, std::true_type>
-    : public truncating_iterator_base<OutputIt> {
- public:
-  truncating_iterator() = default;
-
-  truncating_iterator(OutputIt out, size_t limit)
-      : truncating_iterator_base<OutputIt>(out, limit) {}
-
-  template <typename T> truncating_iterator& operator=(T val) {
-    if (this->count_++ < this->limit_) *this->out_++ = val;
-    return *this;
-  }
-
-  truncating_iterator& operator++() { return *this; }
-  truncating_iterator& operator++(int) { return *this; }
-  truncating_iterator& operator*() { return *this; }
-};
-
 // <algorithm> is spectacularly slow to compile in C++20 so use a simple fill_n
 // instead (#1998).
 template <typename OutputIt, typename Size, typename T>