Allowing formatting non-copyable ranges. (#3290)

fmtlib · Jan 27, 2023 · 05e3a92 · 05e3a92
1 parent 70db193
commit 05e3a92
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Showing 2 changed files with 6 additions and 4 deletions.
diff --git a/include/fmt/ranges.h b/include/fmt/ranges.h
@@ -155,7 +155,9 @@ template <typename T>
 struct has_mutable_begin_end<
     T, void_t<decltype(detail::range_begin(std::declval<T>())),
               decltype(detail::range_end(std::declval<T>())),
-              enable_if_t<std::is_copy_constructible<T>::value>>>
+              // the extra int here is because older versions of MSVC don't
+              // SFINAE properly unless there are distinct types
+              int>>
     : std::true_type {};
 
 template <typename T>

diff --git a/test/ranges-test.cc b/test/ranges-test.cc
@@ -193,7 +193,7 @@ template <typename T> class noncopyable_range {
   std::vector<T> vec;
 
  public:
-  using const_iterator = typename ::std::vector<T>::const_iterator;
+  using iterator = typename ::std::vector<T>::iterator;
 
   template <typename... Args>
   explicit noncopyable_range(Args&&... args)
@@ -202,8 +202,8 @@ template <typename T> class noncopyable_range {
   noncopyable_range(noncopyable_range const&) = delete;
   noncopyable_range(noncopyable_range&) = delete;
 
-  const_iterator begin() const { return vec.begin(); }
-  const_iterator end() const { return vec.end(); }
+  iterator begin() { return vec.begin(); }
+  iterator end() { return vec.end(); }
 };
 
 TEST(ranges_test, range) {