is_file is in file_base.hpp (API Change):

* The metafunction `is_file` is part of file_base.hpp

Actions Required

* Include file_base.hpp as needed

include/boost/beast/core/file_base.hpp

@@ -11,7 +11,9 @@
 #define BOOST_BEAST_CORE_FILE_BASE_HPP
 
 #include <boost/beast/core/detail/config.hpp>
-#include <boost/beast/core/string.hpp>
+#include <boost/beast/core/error.hpp>
+#include <boost/type_traits/make_void.hpp>
+#include <type_traits>
 
 namespace boost {
 namespace beast {
@@ -93,6 +95,69 @@ enum class file_mode
     append_existing
 };
 
+/** Determine if `T` meets the requirements of @b File.
+
+    Metafunctions are used to perform compile time checking of template
+    types. This type will be `std::true_type` if `T` meets the requirements,
+    else the type will be `std::false_type`. 
+
+    @par Example
+
+    Use with `static_assert`:
+
+    @code
+    template<class File>
+    void f(File& file)
+    {
+        static_assert(is_file<File>::value,
+            "File requirements not met");
+    ...
+    @endcode
+
+    Use with `std::enable_if` (SFINAE):
+
+    @code
+    template<class File>
+    typename std::enable_if<is_file<File>::value>::type
+    f(File& file);
+    @endcode
+*/
+#if BOOST_BEAST_DOXYGEN
+template<class T>
+struct is_file : std::integral_constant<bool, ...>{};
+#else
+template<class T, class = void>
+struct is_file : std::false_type {};
+
+template<class T>
+struct is_file<T, boost::void_t<decltype(
+    std::declval<bool&>() = std::declval<T const&>().is_open(),
+    std::declval<T&>().close(std::declval<error_code&>()),
+    std::declval<T&>().open(
+        std::declval<char const*>(),
+        std::declval<file_mode>(),
+        std::declval<error_code&>()),
+    std::declval<std::uint64_t&>() = std::declval<T&>().size(
+        std::declval<error_code&>()),
+    std::declval<std::uint64_t&>() = std::declval<T&>().pos(
+        std::declval<error_code&>()),
+    std::declval<T&>().seek(
+        std::declval<std::uint64_t>(),
+        std::declval<error_code&>()),
+    std::declval<std::size_t&>() = std::declval<T&>().read(
+        std::declval<void*>(),
+        std::declval<std::size_t>(),
+        std::declval<error_code&>()),
+    std::declval<std::size_t&>() = std::declval<T&>().write(
+        std::declval<void const*>(),
+        std::declval<std::size_t>(),
+        std::declval<error_code&>())
+            )>> : std::integral_constant<bool,
+    std::is_default_constructible<T>::value &&
+    std::is_destructible<T>::value
+        > {};
+#endif
+
 } // beast
 } // boost
 

include/boost/beast/core/type_traits.hpp

@@ -56,75 +56,6 @@ using is_completion_handler = std::integral_constant<bool,
     detail::is_invocable<T, Signature>::value>;
 #endif
 
-//------------------------------------------------------------------------------
-//
-// File concepts
-//
-//------------------------------------------------------------------------------
-
-/** Determine if `T` meets the requirements of @b File.
-
-    Metafunctions are used to perform compile time checking of template
-    types. This type will be `std::true_type` if `T` meets the requirements,
-    else the type will be `std::false_type`. 
-
-    @par Example
-
-    Use with `static_assert`:
-
-    @code
-    template<class File>
-    void f(File& file)
-    {
-        static_assert(is_file<File>::value,
-            "File requirements not met");
-    ...
-    @endcode
-
-    Use with `std::enable_if` (SFINAE):
-
-    @code
-    template<class File>
-    typename std::enable_if<is_file<File>::value>::type
-    f(File& file);
-    @endcode
-*/
-#if BOOST_BEAST_DOXYGEN
-template<class T>
-struct is_file : std::integral_constant<bool, ...>{};
-#else
-template<class T, class = void>
-struct is_file : std::false_type {};
-
-template<class T>
-struct is_file<T, detail::void_t<decltype(
-    std::declval<bool&>() = std::declval<T const&>().is_open(),
-    std::declval<T&>().close(std::declval<error_code&>()),
-    std::declval<T&>().open(
-        std::declval<char const*>(),
-        std::declval<file_mode>(),
-        std::declval<error_code&>()),
-    std::declval<std::uint64_t&>() = std::declval<T&>().size(
-        std::declval<error_code&>()),
-    std::declval<std::uint64_t&>() = std::declval<T&>().pos(
-        std::declval<error_code&>()),
-    std::declval<T&>().seek(
-        std::declval<std::uint64_t>(),
-        std::declval<error_code&>()),
-    std::declval<std::size_t&>() = std::declval<T&>().read(
-        std::declval<void*>(),
-        std::declval<std::size_t>(),
-        std::declval<error_code&>()),
-    std::declval<std::size_t&>() = std::declval<T&>().write(
-        std::declval<void const*>(),
-        std::declval<std::size_t>(),
-        std::declval<error_code&>())
-            )>> : std::integral_constant<bool,
-    std::is_default_constructible<T>::value &&
-    std::is_destructible<T>::value
-        > {};
-#endif
-
 } // beast
 } // boost
 

include/boost/beast/http/basic_file_body.hpp

@@ -13,7 +13,6 @@
 #include <boost/beast/core/detail/config.hpp>
 #include <boost/beast/core/error.hpp>
 #include <boost/beast/core/file_base.hpp>
-#include <boost/beast/core/type_traits.hpp>
 #include <boost/beast/http/message.hpp>
 #include <boost/assert.hpp>
 #include <boost/optional.hpp>