buffer_size is in buffer_traits.hpp

test/beast/core/buffer_traits.cpp

@@ -11,11 +11,46 @@
 #include <boost/beast/core/buffer_traits.hpp>
 
 #include <boost/beast/_experimental/unit_test/suite.hpp>
+#include <boost/beast/core/detail/type_traits.hpp>
 #include <array>
 
 namespace boost {
 namespace beast {
 
+namespace {
+
+struct sequence
+{
+    struct value_type
+    {
+        operator net::const_buffer() const noexcept
+        {
+            return {"Hello, world!", 13};
+        }
+    };
+
+    using const_iterator = value_type const*;
+
+    const_iterator begin() const noexcept
+    {
+        return &v_;
+    }
+
+    const_iterator end() const noexcept
+    {
+        return begin() + 1;
+    }
+
+private:
+    value_type v_;
+};
+
+struct not_sequence
+{
+};
+
+} // (anon)
+
 class buffer_traits_test : public beast::unit_test::suite
 {
 public:
@@ -168,9 +203,36 @@ public:
         pass();
     }
 
+    void
+    testFunction()
+    {
+        BEAST_EXPECT(buffer_size(
+            net::const_buffer("Hello, world!", 13)) == 13);
+
+        BEAST_EXPECT(buffer_size(
+            net::mutable_buffer{}) == 0);
+
+        {
+            sequence s;
+            BEAST_EXPECT(buffer_size(s) == 13);
+        }
+
+        {
+            std::array<net::const_buffer, 2> s({{
+                net::const_buffer("Hello, world!", 13),
+                net::const_buffer("Hello, world!", 13)}});
+            BEAST_EXPECT(buffer_size(s) == 26);
+        }
+
+        BOOST_STATIC_ASSERT(! detail::is_invocable<
+            detail::buffer_size_impl,
+            std::size_t(not_sequence const&)>::value);
+    }
+
     void run() override
     {
         testJavadocs();
+        testFunction();
     }
 };