HTTP improvements:

* Increased code coverage

* New Body concepts:
    is_Body
    is_ReadableBody
    is_WritableBody

test/Jamfile

@@ -44,6 +44,7 @@ unit-test http-tests :
     http/basic_headers.cpp
     http/basic_parser_v1.cpp
     http/body_type.cpp
+    http/concepts.cpp
     http/empty_body.cpp
     http/headers.cpp
     http/message.cpp
@@ -58,7 +59,6 @@ unit-test http-tests :
     http/status.cpp
     http/streambuf_body.cpp
     http/string_body.cpp
-    http/type_check.cpp
     http/write.cpp
     http/detail/chunk_encode.cpp
     ;

test/core/buffer_cat.cpp

@@ -66,6 +66,14 @@ public:
             expect(buffer_size(buffer_cat(
                 sb1.data(), sb2.data())) == 12);
         }
+        for(auto it = bs.begin(); it != bs.end(); ++it)
+        {
+            decltype(bs)::const_iterator copy;
+            copy = it;
+            expect(copy == it);
+            copy = copy;
+            expect(copy == it);
+        }
     }
 
     void testIterators()

test/http/CMakeLists.txt

@@ -10,6 +10,7 @@ add_executable (http-tests
     basic_headers.cpp
     basic_parser_v1.cpp
     body_type.cpp
+    concepts.cpp
     empty_body.cpp
     headers.cpp
     message.cpp
@@ -24,7 +25,6 @@ add_executable (http-tests
     status.cpp
     streambuf_body.cpp
     string_body.cpp
-    type_check.cpp
     write.cpp
     detail/chunk_encode.cpp
 )

test/http/concepts.cpp

@@ -6,4 +6,4 @@
 //
 
 // Test that header file is self-contained.
-#include <beast/http/type_check.hpp>
+#include <beast/http/concepts.hpp>

test/http/streambuf_body.cpp

@@ -12,8 +12,10 @@
 #include <beast/http/headers.hpp>
 #include <beast/http/parser_v1.hpp>
 #include <beast/http/read.hpp>
+#include <beast/http/write.hpp>
 #include <beast/test/string_stream.hpp>
 #include <beast/unit_test/suite.hpp>
+#include <boost/lexical_cast.hpp>
 
 namespace beast {
 namespace http {
@@ -25,16 +27,18 @@ class streambuf_body_test : public beast::unit_test::suite
 public:
     void run() override
     {
-        test::string_stream ss(ios_,
+        std::string const s =
             "HTTP/1.1 200 OK\r\n"
             "Server: test\r\n"
             "Content-Length: 3\r\n"
             "\r\n"
-            "xyz");
+            "xyz";
+        test::string_stream ss(ios_, s);
         parser_v1<false, streambuf_body, headers> p;
         streambuf sb;
         parse(ss, sb, p);
         expect(to_string(p.get().body.data()) == "xyz");
+        expect(boost::lexical_cast<std::string>(p.get()) == s);
     }
 };