diff --git a/CHANGELOG.md b/CHANGELOG.md
index f1f6179c..95ec785e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,6 +3,7 @@
 API Changes:
 
 * Invoke callback on pings and pongs
+* Move basic_streambuf to streambuf.hpp
 
 --------------------------------------------------------------------------------
 
diff --git a/include/beast/core.hpp b/include/beast/core.hpp
index a46ad003..74525890 100644
--- a/include/beast/core.hpp
+++ b/include/beast/core.hpp
@@ -9,7 +9,6 @@
 #define BEAST_CORE_HPP
 
 #include <beast/core/async_completion.hpp>
-#include <beast/core/basic_streambuf.hpp>
 #include <beast/core/bind_handler.hpp>
 #include <beast/core/buffer_cat.hpp>
 #include <beast/core/buffer_concepts.hpp>
diff --git a/include/beast/core/basic_streambuf.hpp b/include/beast/core/basic_streambuf.hpp
deleted file mode 100644
index 9dac4c06..00000000
--- a/include/beast/core/basic_streambuf.hpp
+++ /dev/null
@@ -1,333 +0,0 @@
-//
-// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
-//
-// Distributed under the Boost Software License, Version 1.0. (See accompanying
-// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//
-
-#ifndef BEAST_BASIC_STREAMBUF_HPP
-#define BEAST_BASIC_STREAMBUF_HPP
-
-#include <beast/core/detail/empty_base_optimization.hpp>
-#include <boost/asio/buffer.hpp>
-#include <boost/intrusive/list.hpp>
-#include <iterator>
-#include <limits>
-#include <memory>
-#include <type_traits>
-
-namespace beast {
-
-/** A @b `DynamicBuffer` that uses multiple buffers internally.
-
-    The implementation uses a sequence of one or more character arrays
-    of varying sizes. Additional character array objects are appended to
-    the sequence to accommodate changes in the size of the character
-    sequence.
-
-    @note Meets the requirements of @b DynamicBuffer.
-
-    @tparam Allocator The allocator to use for managing memory.
-*/
-template<class Allocator>
-class basic_streambuf
-#if ! GENERATING_DOCS
-    : private detail::empty_base_optimization<
-        typename std::allocator_traits<Allocator>::
-            template rebind_alloc<std::uint8_t>>
-#endif
-{
-public:
-#if GENERATING_DOCS
-    /// The type of allocator used.
-    using allocator_type = Allocator;
-#else
-    using allocator_type = typename
-        std::allocator_traits<Allocator>::
-            template rebind_alloc<std::uint8_t>;
-#endif
-
-private:
-    // Storage for the list of buffers representing the input
-    // and output sequences. The allocation for each element
-    // contains `element` followed by raw storage bytes.
-    class element;
-
-    using alloc_traits = std::allocator_traits<allocator_type>;
-    using list_type = typename boost::intrusive::make_list<element,
-        boost::intrusive::constant_time_size<true>>::type;
-    using iterator = typename list_type::iterator;
-    using const_iterator = typename list_type::const_iterator;
-
-    using size_type = typename std::allocator_traits<Allocator>::size_type;
-    using const_buffer = boost::asio::const_buffer;
-    using mutable_buffer = boost::asio::mutable_buffer;
-
-    static_assert(std::is_base_of<std::bidirectional_iterator_tag,
-        typename std::iterator_traits<iterator>::iterator_category>::value,
-            "BidirectionalIterator requirements not met");
-
-    static_assert(std::is_base_of<std::bidirectional_iterator_tag,
-        typename std::iterator_traits<const_iterator>::iterator_category>::value,
-            "BidirectionalIterator requirements not met");
-
-    list_type list_;        // list of allocated buffers
-    iterator out_;          // element that contains out_pos_
-    size_type alloc_size_;  // min amount to allocate
-    size_type in_size_ = 0; // size of the input sequence
-    size_type in_pos_ = 0;  // input offset in list_.front()
-    size_type out_pos_ = 0; // output offset in *out_
-    size_type out_end_ = 0; // output end offset in list_.back()
-
-public:
-#if GENERATING_DOCS
-    /// The type used to represent the input sequence as a list of buffers.
-    using const_buffers_type = implementation_defined;
-
-    /// The type used to represent the output sequence as a list of buffers.
-    using mutable_buffers_type = implementation_defined;
-
-#else
-    class const_buffers_type;
-
-    class mutable_buffers_type;
-
-#endif
-
-    /// Destructor.
-    ~basic_streambuf();
-
-    /** Move constructor.
-
-        The new object will have the input sequence of
-        the other stream buffer, and an empty output sequence.
-
-        @note After the move, the moved-from object will have
-        an empty input and output sequence, with no internal
-        buffers allocated.
-    */
-    basic_streambuf(basic_streambuf&&);
-
-    /** Move constructor.
-
-        The new object will have the input sequence of
-        the other stream buffer, and an empty output sequence.
-
-        @note After the move, the moved-from object will have
-        an empty input and output sequence, with no internal
-        buffers allocated.
-
-        @param alloc The allocator to associate with the
-        stream buffer.
-    */
-    basic_streambuf(basic_streambuf&&,
-        allocator_type const& alloc);
-
-    /** Move assignment.
-
-        This object will have the input sequence of
-        the other stream buffer, and an empty output sequence.
-
-        @note After the move, the moved-from object will have
-        an empty input and output sequence, with no internal
-        buffers allocated.
-    */
-    basic_streambuf&
-    operator=(basic_streambuf&&);
-
-    /** Copy constructor.
-
-        This object will have a copy of the other stream
-        buffer's input sequence, and an empty output sequence.
-    */
-    basic_streambuf(basic_streambuf const&);
-
-    /** Copy constructor.
-
-        This object will have a copy of the other stream
-        buffer's input sequence, and an empty output sequence.
-
-        @param alloc The allocator to associate with the
-        stream buffer.
-    */
-    basic_streambuf(basic_streambuf const&,
-        allocator_type const& alloc);
-
-    /** Copy assignment.
-
-        This object will have a copy of the other stream
-        buffer's input sequence, and an empty output sequence.
-    */
-    basic_streambuf& operator=(basic_streambuf const&);
-
-    /** Copy constructor.
-
-        This object will have a copy of the other stream
-        buffer's input sequence, and an empty output sequence.
-    */
-    template<class OtherAlloc>
-    basic_streambuf(basic_streambuf<OtherAlloc> const&);
-
-    /** Copy constructor.
-
-        This object will have a copy of the other stream
-        buffer's input sequence, and an empty output sequence.
-
-        @param alloc The allocator to associate with the
-        stream buffer.
-    */
-    template<class OtherAlloc>
-    basic_streambuf(basic_streambuf<OtherAlloc> const&,
-        allocator_type const& alloc);
-
-    /** Copy assignment.
-
-        This object will have a copy of the other stream
-        buffer's input sequence, and an empty output sequence.
-    */
-    template<class OtherAlloc>
-    basic_streambuf& operator=(basic_streambuf<OtherAlloc> const&);
-
-    /** Construct a stream buffer.
-
-        @param alloc_size The size of buffer to allocate. This is a
-        soft limit, calls to prepare for buffers exceeding this size
-        will allocate the larger size. The default allocation size
-        is 1KB (1024 bytes).
-
-        @param alloc The allocator to use. If this parameter is
-        unspecified, a default constructed allocator will be used.
-    */
-    explicit
-    basic_streambuf(std::size_t alloc_size = 1024,
-        Allocator const& alloc = allocator_type{});
-
-    /// Returns a copy of the associated allocator.
-    allocator_type
-    get_allocator() const
-    {
-        return this->member();
-    }
-
-    /** Returns the default allocation size.
-
-        This is the smallest size that the stream buffer will allocate.
-        The size of the allocation can influence capacity, which will
-        affect algorithms that use capacity to efficiently read from
-        streams.
-    */
-    std::size_t
-    alloc_size() const
-    {
-        return alloc_size_;
-    }
-
-    /** Set the default allocation size.
-
-        This is the smallest size that the stream buffer will allocate.
-        The size of the allocation can influence capacity, which will
-        affect algorithms that use capacity to efficiently read from
-        streams.
-
-        @note This will not affect any already-existing allocations.
-
-        @param n The number of bytes.
-    */
-    void
-    alloc_size(std::size_t n)
-    {
-        alloc_size_ = n;
-    }
-
-    /// Returns the size of the input sequence.
-    size_type
-    size() const
-    {
-        return in_size_;
-    }
-
-    /// Returns the permitted maximum sum of the sizes of the input and output sequence.
-    size_type
-    max_size() const
-    {
-        return (std::numeric_limits<std::size_t>::max)();
-    }
-
-    /// Returns the maximum sum of the sizes of the input sequence and output sequence the buffer can hold without requiring reallocation.
-    std::size_t
-    capacity() const;
-
-    /** Get a list of buffers that represents the input sequence.
-
-        @note These buffers remain valid across subsequent calls to `prepare`.
-    */
-    const_buffers_type
-    data() const;
-
-    /** Get a list of buffers that represents the output sequence, with the given size.
-
-        @note Buffers representing the input sequence acquired prior to
-        this call remain valid.
-    */
-    mutable_buffers_type
-    prepare(size_type n);
-
-    /** Move bytes from the output sequence to the input sequence.
-
-        @note Buffers representing the input sequence acquired prior to
-        this call remain valid.
-    */
-    void
-    commit(size_type n);
-
-    /// Remove bytes from the input sequence.
-    void
-    consume(size_type n);
-
-    // Helper for boost::asio::read_until
-    template<class OtherAllocator>
-    friend
-    std::size_t
-    read_size_helper(basic_streambuf<
-        OtherAllocator> const& streambuf, std::size_t max_size);
-
-private:
-    void
-    clear();
-
-    void
-    move_assign(basic_streambuf& other, std::false_type);
-
-    void
-    move_assign(basic_streambuf& other, std::true_type);
-
-    void
-    copy_assign(basic_streambuf const& other, std::false_type);
-
-    void
-    copy_assign(basic_streambuf const& other, std::true_type);
-
-    void
-    delete_list();
-
-    void
-    debug_check() const;
-};
-
-/** Format output to a @ref basic_streambuf.
-
-    @param streambuf The @ref basic_streambuf to write to.
-
-    @param t The object to write.
-
-    @return A reference to the @ref basic_streambuf.
-*/
-template<class Allocator, class T>
-basic_streambuf<Allocator>&
-operator<<(basic_streambuf<Allocator>& streambuf, T const& t);
-
-} // beast
-
-#include <beast/core/impl/basic_streambuf.ipp>
-
-#endif
diff --git a/include/beast/core/impl/basic_streambuf.ipp b/include/beast/core/impl/streambuf.ipp
similarity index 98%
rename from include/beast/core/impl/basic_streambuf.ipp
rename to include/beast/core/impl/streambuf.ipp
index 710a5a1a..5844c8fb 100644
--- a/include/beast/core/impl/basic_streambuf.ipp
+++ b/include/beast/core/impl/streambuf.ipp
@@ -5,8 +5,8 @@
 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
 //
 
-#ifndef BEAST_IMPL_BASIC_STREAMBUF_IPP
-#define BEAST_IMPL_BASIC_STREAMBUF_IPP
+#ifndef BEAST_IMPL_STREAMBUF_IPP
+#define BEAST_IMPL_STREAMBUF_IPP
 
 #include <beast/core/detail/type_traits.hpp>
 #include <beast/core/detail/write_dynabuf.hpp>
@@ -624,7 +624,7 @@ basic_streambuf<Allocator>::prepare(size_type n) ->
         auto const len = e.size() + sizeof(e);
         alloc_traits::destroy(this->member(), &e);
         alloc_traits::deallocate(this->member(),
-            reinterpret_cast<std::uint8_t*>(&e), len);
+            reinterpret_cast<char*>(&e), len);
     }
     return mutable_buffers_type(*this);
 }
@@ -696,7 +696,7 @@ basic_streambuf<Allocator>::consume(size_type n)
             auto const len = e.size() + sizeof(e);
             alloc_traits::destroy(this->member(), &e);
             alloc_traits::deallocate(this->member(),
-                reinterpret_cast<std::uint8_t*>(&e), len);
+                reinterpret_cast<char*>(&e), len);
             debug_check();
         }
         else
@@ -808,7 +808,7 @@ basic_streambuf<Allocator>::delete_list()
         auto const n = e.size() + sizeof(e);
         alloc_traits::destroy(this->member(), &e);
         alloc_traits::deallocate(this->member(),
-            reinterpret_cast<std::uint8_t*>(&e), n);
+            reinterpret_cast<char*>(&e), n);
     }
 }
 
diff --git a/include/beast/core/streambuf.hpp b/include/beast/core/streambuf.hpp
index 1726543f..401de0b1 100644
--- a/include/beast/core/streambuf.hpp
+++ b/include/beast/core/streambuf.hpp
@@ -8,10 +8,312 @@
 #ifndef BEAST_STREAMBUF_HPP
 #define BEAST_STREAMBUF_HPP
 
-#include <beast/core/basic_streambuf.hpp>
+#include <beast/core/detail/empty_base_optimization.hpp>
+#include <boost/asio/buffer.hpp>
+#include <boost/intrusive/list.hpp>
+#include <iterator>
+#include <limits>
+#include <memory>
+#include <type_traits>
 
 namespace beast {
 
+/** A @b `DynamicBuffer` that uses multiple buffers internally.
+
+    The implementation uses a sequence of one or more character arrays
+    of varying sizes. Additional character array objects are appended to
+    the sequence to accommodate changes in the size of the character
+    sequence.
+
+    @note Meets the requirements of @b DynamicBuffer.
+
+    @tparam Allocator The allocator to use for managing memory.
+*/
+template<class Allocator>
+class basic_streambuf
+#if ! GENERATING_DOCS
+    : private detail::empty_base_optimization<
+        typename std::allocator_traits<Allocator>::
+            template rebind_alloc<char>>
+#endif
+{
+public:
+#if GENERATING_DOCS
+    /// The type of allocator used.
+    using allocator_type = Allocator;
+#else
+    using allocator_type = typename
+        std::allocator_traits<Allocator>::
+            template rebind_alloc<char>;
+#endif
+
+private:
+    // Storage for the list of buffers representing the input
+    // and output sequences. The allocation for each element
+    // contains `element` followed by raw storage bytes.
+    class element;
+
+    using alloc_traits = std::allocator_traits<allocator_type>;
+    using list_type = typename boost::intrusive::make_list<element,
+        boost::intrusive::constant_time_size<true>>::type;
+    using iterator = typename list_type::iterator;
+    using const_iterator = typename list_type::const_iterator;
+
+    using size_type = typename std::allocator_traits<Allocator>::size_type;
+    using const_buffer = boost::asio::const_buffer;
+    using mutable_buffer = boost::asio::mutable_buffer;
+
+    static_assert(std::is_base_of<std::bidirectional_iterator_tag,
+        typename std::iterator_traits<iterator>::iterator_category>::value,
+            "BidirectionalIterator requirements not met");
+
+    static_assert(std::is_base_of<std::bidirectional_iterator_tag,
+        typename std::iterator_traits<const_iterator>::iterator_category>::value,
+            "BidirectionalIterator requirements not met");
+
+    list_type list_;        // list of allocated buffers
+    iterator out_;          // element that contains out_pos_
+    size_type alloc_size_;  // min amount to allocate
+    size_type in_size_ = 0; // size of the input sequence
+    size_type in_pos_ = 0;  // input offset in list_.front()
+    size_type out_pos_ = 0; // output offset in *out_
+    size_type out_end_ = 0; // output end offset in list_.back()
+
+public:
+#if GENERATING_DOCS
+    /// The type used to represent the input sequence as a list of buffers.
+    using const_buffers_type = implementation_defined;
+
+    /// The type used to represent the output sequence as a list of buffers.
+    using mutable_buffers_type = implementation_defined;
+
+#else
+    class const_buffers_type;
+
+    class mutable_buffers_type;
+
+#endif
+
+    /// Destructor.
+    ~basic_streambuf();
+
+    /** Move constructor.
+
+        The new object will have the input sequence of
+        the other stream buffer, and an empty output sequence.
+
+        @note After the move, the moved-from object will have
+        an empty input and output sequence, with no internal
+        buffers allocated.
+    */
+    basic_streambuf(basic_streambuf&&);
+
+    /** Move constructor.
+
+        The new object will have the input sequence of
+        the other stream buffer, and an empty output sequence.
+
+        @note After the move, the moved-from object will have
+        an empty input and output sequence, with no internal
+        buffers allocated.
+
+        @param alloc The allocator to associate with the
+        stream buffer.
+    */
+    basic_streambuf(basic_streambuf&&,
+        allocator_type const& alloc);
+
+    /** Move assignment.
+
+        This object will have the input sequence of
+        the other stream buffer, and an empty output sequence.
+
+        @note After the move, the moved-from object will have
+        an empty input and output sequence, with no internal
+        buffers allocated.
+    */
+    basic_streambuf&
+    operator=(basic_streambuf&&);
+
+    /** Copy constructor.
+
+        This object will have a copy of the other stream
+        buffer's input sequence, and an empty output sequence.
+    */
+    basic_streambuf(basic_streambuf const&);
+
+    /** Copy constructor.
+
+        This object will have a copy of the other stream
+        buffer's input sequence, and an empty output sequence.
+
+        @param alloc The allocator to associate with the
+        stream buffer.
+    */
+    basic_streambuf(basic_streambuf const&,
+        allocator_type const& alloc);
+
+    /** Copy assignment.
+
+        This object will have a copy of the other stream
+        buffer's input sequence, and an empty output sequence.
+    */
+    basic_streambuf& operator=(basic_streambuf const&);
+
+    /** Copy constructor.
+
+        This object will have a copy of the other stream
+        buffer's input sequence, and an empty output sequence.
+    */
+    template<class OtherAlloc>
+    basic_streambuf(basic_streambuf<OtherAlloc> const&);
+
+    /** Copy constructor.
+
+        This object will have a copy of the other stream
+        buffer's input sequence, and an empty output sequence.
+
+        @param alloc The allocator to associate with the
+        stream buffer.
+    */
+    template<class OtherAlloc>
+    basic_streambuf(basic_streambuf<OtherAlloc> const&,
+        allocator_type const& alloc);
+
+    /** Copy assignment.
+
+        This object will have a copy of the other stream
+        buffer's input sequence, and an empty output sequence.
+    */
+    template<class OtherAlloc>
+    basic_streambuf& operator=(basic_streambuf<OtherAlloc> const&);
+
+    /** Construct a stream buffer.
+
+        @param alloc_size The size of buffer to allocate. This is a
+        soft limit, calls to prepare for buffers exceeding this size
+        will allocate the larger size. The default allocation size
+        is 1KB (1024 bytes).
+
+        @param alloc The allocator to use. If this parameter is
+        unspecified, a default constructed allocator will be used.
+    */
+    explicit
+    basic_streambuf(std::size_t alloc_size = 1024,
+        Allocator const& alloc = allocator_type{});
+
+    /// Returns a copy of the associated allocator.
+    allocator_type
+    get_allocator() const
+    {
+        return this->member();
+    }
+
+    /** Returns the default allocation size.
+
+        This is the smallest size that the stream buffer will allocate.
+        The size of the allocation can influence capacity, which will
+        affect algorithms that use capacity to efficiently read from
+        streams.
+    */
+    std::size_t
+    alloc_size() const
+    {
+        return alloc_size_;
+    }
+
+    /** Set the default allocation size.
+
+        This is the smallest size that the stream buffer will allocate.
+        The size of the allocation can influence capacity, which will
+        affect algorithms that use capacity to efficiently read from
+        streams.
+
+        @note This will not affect any already-existing allocations.
+
+        @param n The number of bytes.
+    */
+    void
+    alloc_size(std::size_t n)
+    {
+        alloc_size_ = n;
+    }
+
+    /// Returns the size of the input sequence.
+    size_type
+    size() const
+    {
+        return in_size_;
+    }
+
+    /// Returns the permitted maximum sum of the sizes of the input and output sequence.
+    size_type
+    max_size() const
+    {
+        return (std::numeric_limits<std::size_t>::max)();
+    }
+
+    /// Returns the maximum sum of the sizes of the input sequence and output sequence the buffer can hold without requiring reallocation.
+    std::size_t
+    capacity() const;
+
+    /** Get a list of buffers that represents the input sequence.
+
+        @note These buffers remain valid across subsequent calls to `prepare`.
+    */
+    const_buffers_type
+    data() const;
+
+    /** Get a list of buffers that represents the output sequence, with the given size.
+
+        @note Buffers representing the input sequence acquired prior to
+        this call remain valid.
+    */
+    mutable_buffers_type
+    prepare(size_type n);
+
+    /** Move bytes from the output sequence to the input sequence.
+
+        @note Buffers representing the input sequence acquired prior to
+        this call remain valid.
+    */
+    void
+    commit(size_type n);
+
+    /// Remove bytes from the input sequence.
+    void
+    consume(size_type n);
+
+    // Helper for boost::asio::read_until
+    template<class OtherAllocator>
+    friend
+    std::size_t
+    read_size_helper(basic_streambuf<
+        OtherAllocator> const& streambuf, std::size_t max_size);
+
+private:
+    void
+    clear();
+
+    void
+    move_assign(basic_streambuf& other, std::false_type);
+
+    void
+    move_assign(basic_streambuf& other, std::true_type);
+
+    void
+    copy_assign(basic_streambuf const& other, std::false_type);
+
+    void
+    copy_assign(basic_streambuf const& other, std::true_type);
+
+    void
+    delete_list();
+
+    void
+    debug_check() const;
+};
+
 /** A @b `DynamicBuffer` that uses multiple buffers internally.
 
     The implementation uses a sequence of one or more character arrays
@@ -23,6 +325,20 @@ namespace beast {
 */
 using streambuf = basic_streambuf<std::allocator<char>>;
 
+/** Format output to a @ref basic_streambuf.
+
+    @param streambuf The @ref basic_streambuf to write to.
+
+    @param t The object to write.
+
+    @return A reference to the @ref basic_streambuf.
+*/
+template<class Allocator, class T>
+basic_streambuf<Allocator>&
+operator<<(basic_streambuf<Allocator>& streambuf, T const& t);
+
 } // beast
 
+#include <beast/core/impl/streambuf.ipp>
+
 #endif
diff --git a/test/Jamfile b/test/Jamfile
index 5ffb5d59..6b8c52c1 100644
--- a/test/Jamfile
+++ b/test/Jamfile
@@ -16,7 +16,6 @@ compile zlib.cpp : : ;
 unit-test core-tests :
     ../extras/beast/unit_test/main.cpp
     core/async_completion.cpp
-    core/basic_streambuf.cpp
     core/bind_handler.cpp
     core/buffer_cat.cpp
     core/buffer_concepts.cpp
diff --git a/test/core/CMakeLists.txt b/test/core/CMakeLists.txt
index 1ef6f5a7..ad5aa722 100644
--- a/test/core/CMakeLists.txt
+++ b/test/core/CMakeLists.txt
@@ -10,7 +10,6 @@ add_executable (core-tests
     ../../extras/beast/unit_test/main.cpp
     buffer_test.hpp
     async_completion.cpp
-    basic_streambuf.cpp
     bind_handler.cpp
     buffer_cat.cpp
     buffer_concepts.cpp
diff --git a/test/core/basic_streambuf.cpp b/test/core/basic_streambuf.cpp
deleted file mode 100644
index 00b468dd..00000000
--- a/test/core/basic_streambuf.cpp
+++ /dev/null
@@ -1,480 +0,0 @@
-//
-// Copyright (c) 2013-2016 Vinnie Falco (vinnie dot falco at gmail dot com)
-//
-// Distributed under the Boost Software License, Version 1.0. (See accompanying
-// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
-//
-
-// Test that header file is self-contained.
-#include <beast/core/basic_streambuf.hpp>
-
-#include "buffer_test.hpp"
-#include <beast/core/streambuf.hpp>
-#include <beast/core/to_string.hpp>
-#include <beast/unit_test/suite.hpp>
-#include <boost/asio/buffer.hpp>
-#include <algorithm>
-#include <atomic>
-#include <memory>
-#include <string>
-
-namespace beast {
-
-struct test_allocator_info
-{
-    std::size_t ncopy = 0;
-    std::size_t nmove = 0;
-    std::size_t nselect = 0;
-};
-
-template<class T,
-    bool Assign, bool Move, bool Swap, bool Select>
-class test_allocator;
-
-template<class T,
-    bool Assign, bool Move, bool Swap, bool Select>
-struct test_allocator_base
-{
-};
-
-template<class T,
-    bool Assign, bool Move, bool Swap>
-struct test_allocator_base<T, Assign, Move, Swap, true>
-{
-    static
-    test_allocator<T, Assign, Move, Swap, true>
-    select_on_container_copy_construction(
-        test_allocator<T, Assign, Move, Swap, true> const& a)
-    {
-        return test_allocator<T, Assign, Move, Swap, true>{};
-    }
-};
-
-template<class T,
-    bool Assign, bool Move, bool Swap, bool Select>
-class test_allocator : public test_allocator_base<
-        T, Assign, Move, Swap, Select>
-{
-    std::size_t id_;
-    std::shared_ptr<test_allocator_info> info_;
-
-    template<class, bool, bool, bool, bool>
-    friend class test_allocator;
-
-public:
-    using value_type = T;
-    using propagate_on_container_copy_assignment =
-        std::integral_constant<bool, Assign>;
-    using propagate_on_container_move_assignment =
-        std::integral_constant<bool, Move>;
-    using propagate_on_container_swap =
-        std::integral_constant<bool, Swap>;
-
-    template<class U>
-    struct rebind
-    {
-        using other = test_allocator<
-            U, Assign, Move, Swap, Select>;
-    };
-
-    test_allocator()
-        : id_([]
-            {
-                static std::atomic<
-                    std::size_t> sid(0);
-                return ++sid;
-            }())
-        , info_(std::make_shared<test_allocator_info>())
-    {
-    }
-
-    test_allocator(test_allocator const& u) noexcept
-        : id_(u.id_)
-        , info_(u.info_)
-    {
-        ++info_->ncopy;
-    }
-
-    template<class U>
-    test_allocator(test_allocator<
-            U, Assign, Move, Swap, Select> const& u) noexcept
-        : id_(u.id_)
-        , info_(u.info_)
-    {
-        ++info_->ncopy;
-    }
-
-    test_allocator(test_allocator&& t)
-        : id_(t.id_)
-        , info_(t.info_)
-    {
-        ++info_->nmove;
-    }
-
-    value_type*
-    allocate(std::size_t n)
-    {
-        return static_cast<value_type*>(
-            ::operator new (n*sizeof(value_type)));
-    }
-
-    void
-    deallocate(value_type* p, std::size_t) noexcept
-    {
-        ::operator delete(p);
-    }
-
-    std::size_t
-    id() const
-    {
-        return id_;
-    }
-
-    test_allocator_info const*
-    operator->() const
-    {
-        return info_.get();
-    }
-};
-
-class basic_streambuf_test : public beast::unit_test::suite
-{
-public:
-    template<class Alloc1, class Alloc2>
-    static
-    bool
-    eq(basic_streambuf<Alloc1> const& sb1,
-        basic_streambuf<Alloc2> const& sb2)
-    {
-        return to_string(sb1.data()) == to_string(sb2.data());
-    }
-
-    template<class ConstBufferSequence>
-    void
-    expect_size(std::size_t n, ConstBufferSequence const& buffers)
-    {
-        BEAST_EXPECT(test::size_pre(buffers) == n);
-        BEAST_EXPECT(test::size_post(buffers) == n);
-        BEAST_EXPECT(test::size_rev_pre(buffers) == n);
-        BEAST_EXPECT(test::size_rev_post(buffers) == n);
-    }
-
-    template<class U, class V>
-    static
-    void
-    self_assign(U& u, V&& v)
-    {
-        u = std::forward<V>(v);
-    }
-
-    void testSpecialMembers()
-    {
-        using boost::asio::buffer;
-        using boost::asio::buffer_cast;
-        using boost::asio::buffer_size;
-        std::string const s = "Hello, world";
-        BEAST_EXPECT(s.size() == 12);
-        for(std::size_t i = 1; i < 12; ++i) {
-        for(std::size_t x = 1; x < 4; ++x) {
-        for(std::size_t y = 1; y < 4; ++y) {
-        std::size_t z = s.size() - (x + y);
-        {
-            streambuf sb(i);
-            sb.commit(buffer_copy(sb.prepare(x), buffer(s.data(), x)));
-            sb.commit(buffer_copy(sb.prepare(y), buffer(s.data()+x, y)));
-            sb.commit(buffer_copy(sb.prepare(z), buffer(s.data()+x+y, z)));
-            BEAST_EXPECT(to_string(sb.data()) == s);
-            {
-                streambuf sb2(sb);
-                BEAST_EXPECT(eq(sb, sb2));
-            }
-            {
-                streambuf sb2;
-                sb2 = sb;
-                BEAST_EXPECT(eq(sb, sb2));
-            }
-            {
-                streambuf sb2(std::move(sb));
-                BEAST_EXPECT(to_string(sb2.data()) == s);
-                expect_size(0, sb.data());
-                sb = std::move(sb2);
-                BEAST_EXPECT(to_string(sb.data()) == s);
-                expect_size(0, sb2.data());
-            }
-            self_assign(sb, sb);
-            BEAST_EXPECT(to_string(sb.data()) == s);
-            self_assign(sb, std::move(sb));
-            BEAST_EXPECT(to_string(sb.data()) == s);
-        }
-        }}}
-        try
-        {
-            streambuf sb0(0);
-            fail();
-        }
-        catch(std::exception const&)
-        {
-            pass();
-        }
-    }
-
-    void testAllocator()
-    {
-        // VFALCO This needs work
-        {
-            using alloc_type =
-                test_allocator<char, false, false, false, false>;
-            using sb_type = basic_streambuf<alloc_type>;
-            sb_type sb;
-            BEAST_EXPECT(sb.get_allocator().id() == 1);
-        }
-        {
-            using alloc_type =
-                test_allocator<char, false, false, false, false>;
-            using sb_type = basic_streambuf<alloc_type>;
-            sb_type sb;
-            BEAST_EXPECT(sb.get_allocator().id() == 2);
-            sb_type sb2(sb);
-            BEAST_EXPECT(sb2.get_allocator().id() == 2);
-            sb_type sb3(sb, alloc_type{});
-        }
-    }
-
-    void
-    testPrepare()
-    {
-        using boost::asio::buffer_size;
-        {
-            streambuf sb(2);
-            BEAST_EXPECT(buffer_size(sb.prepare(5)) == 5);
-            BEAST_EXPECT(buffer_size(sb.prepare(8)) == 8);
-            BEAST_EXPECT(buffer_size(sb.prepare(7)) == 7);
-        }
-        {
-            streambuf sb(2);
-            sb.prepare(2);
-            BEAST_EXPECT(test::buffer_count(sb.prepare(5)) == 2);
-            BEAST_EXPECT(test::buffer_count(sb.prepare(8)) == 3);
-            BEAST_EXPECT(test::buffer_count(sb.prepare(4)) == 2);
-        }
-    }
-
-    void testCommit()
-    {
-        using boost::asio::buffer_size;
-        streambuf sb(2);
-        sb.prepare(2);
-        sb.prepare(5);
-        sb.commit(1);
-        expect_size(1, sb.data());
-    }
-
-    void testConsume()
-    {
-        using boost::asio::buffer_size;
-        streambuf sb(1);
-        expect_size(5, sb.prepare(5));
-        sb.commit(3);
-        expect_size(3, sb.data());
-        sb.consume(1);
-        expect_size(2, sb.data());
-    }
-
-    void testMatrix()
-    {
-        using boost::asio::buffer;
-        using boost::asio::buffer_cast;
-        using boost::asio::buffer_size;
-        std::string const s = "Hello, world";
-        BEAST_EXPECT(s.size() == 12);
-        for(std::size_t i = 1; i < 12; ++i) {
-        for(std::size_t x = 1; x < 4; ++x) {
-        for(std::size_t y = 1; y < 4; ++y) {
-        for(std::size_t t = 1; t < 4; ++ t) {
-        for(std::size_t u = 1; u < 4; ++ u) {
-        std::size_t z = s.size() - (x + y);
-        std::size_t v = s.size() - (t + u);
-        {
-            streambuf sb(i);
-            {
-                auto d = sb.prepare(z);
-                BEAST_EXPECT(buffer_size(d) == z);
-            }
-            {
-                auto d = sb.prepare(0);
-                BEAST_EXPECT(buffer_size(d) == 0);
-            }
-            {
-                auto d = sb.prepare(y);
-                BEAST_EXPECT(buffer_size(d) == y);
-            }
-            {
-                auto d = sb.prepare(x);
-                BEAST_EXPECT(buffer_size(d) == x);
-                sb.commit(buffer_copy(d, buffer(s.data(), x)));
-            }
-            BEAST_EXPECT(sb.size() == x);
-            BEAST_EXPECT(buffer_size(sb.data()) == sb.size());
-            {
-                auto d = sb.prepare(x);
-                BEAST_EXPECT(buffer_size(d) == x);
-            }
-            {
-                auto d = sb.prepare(0);
-                BEAST_EXPECT(buffer_size(d) == 0);
-            }
-            {
-                auto d = sb.prepare(z);
-                BEAST_EXPECT(buffer_size(d) == z);
-            }
-            {
-                auto d = sb.prepare(y);
-                BEAST_EXPECT(buffer_size(d) == y);
-                sb.commit(buffer_copy(d, buffer(s.data()+x, y)));
-            }
-            sb.commit(1);
-            BEAST_EXPECT(sb.size() == x + y);
-            BEAST_EXPECT(buffer_size(sb.data()) == sb.size());
-            {
-                auto d = sb.prepare(x);
-                BEAST_EXPECT(buffer_size(d) == x);
-            }
-            {
-                auto d = sb.prepare(y);
-                BEAST_EXPECT(buffer_size(d) == y);
-            }
-            {
-                auto d = sb.prepare(0);
-                BEAST_EXPECT(buffer_size(d) == 0);
-            }
-            {
-                auto d = sb.prepare(z);
-                BEAST_EXPECT(buffer_size(d) == z);
-                sb.commit(buffer_copy(d, buffer(s.data()+x+y, z)));
-            }
-            sb.commit(2);
-            BEAST_EXPECT(sb.size() == x + y + z);
-            BEAST_EXPECT(buffer_size(sb.data()) == sb.size());
-            BEAST_EXPECT(to_string(sb.data()) == s);
-            sb.consume(t);
-            {
-                auto d = sb.prepare(0);
-                BEAST_EXPECT(buffer_size(d) == 0);
-            }
-            BEAST_EXPECT(to_string(sb.data()) == s.substr(t, std::string::npos));
-            sb.consume(u);
-            BEAST_EXPECT(to_string(sb.data()) == s.substr(t + u, std::string::npos));
-            sb.consume(v);
-            BEAST_EXPECT(to_string(sb.data()) == "");
-            sb.consume(1);
-            {
-                auto d = sb.prepare(0);
-                BEAST_EXPECT(buffer_size(d) == 0);
-            }
-        }
-        }}}}}
-    }
-
-    void testIterators()
-    {
-        using boost::asio::buffer_size;
-        streambuf sb(1);
-        sb.prepare(1);
-        sb.commit(1);
-        sb.prepare(2);
-        sb.commit(2);
-        expect_size(3, sb.data());
-        sb.prepare(1);
-        expect_size(3, sb.prepare(3));
-        sb.commit(2);
-        BEAST_EXPECT(test::buffer_count(sb.data()) == 4);
-    }
-
-    void testOutputStream()
-    {
-        streambuf sb;
-        sb << "x";
-        BEAST_EXPECT(to_string(sb.data()) == "x");
-    }
-
-    void testCapacity()
-    {
-        using boost::asio::buffer_size;
-        {
-            streambuf sb{10};
-            BEAST_EXPECT(sb.alloc_size() == 10);
-            BEAST_EXPECT(read_size_helper(sb, 1) == 1);
-            BEAST_EXPECT(read_size_helper(sb, 10) == 10);
-            BEAST_EXPECT(read_size_helper(sb, 20) == 20);
-            BEAST_EXPECT(read_size_helper(sb, 1000) == 512);
-            sb.prepare(3);
-            sb.commit(3);
-            BEAST_EXPECT(read_size_helper(sb, 10) == 7);
-            BEAST_EXPECT(read_size_helper(sb, 1000) == 7);
-        }
-        {
-            streambuf sb(1000);
-            BEAST_EXPECT(sb.alloc_size() == 1000);
-            BEAST_EXPECT(read_size_helper(sb, 1) == 1);
-            BEAST_EXPECT(read_size_helper(sb, 1000) == 1000);
-            BEAST_EXPECT(read_size_helper(sb, 2000) == 1000);
-            sb.prepare(3);
-            BEAST_EXPECT(read_size_helper(sb, 1) == 1);
-            BEAST_EXPECT(read_size_helper(sb, 1000) == 1000);
-            BEAST_EXPECT(read_size_helper(sb, 2000) == 1000);
-            sb.commit(3);
-            BEAST_EXPECT(read_size_helper(sb, 1) == 1);
-            BEAST_EXPECT(read_size_helper(sb, 1000) == 997);
-            BEAST_EXPECT(read_size_helper(sb, 2000) == 997);
-            sb.consume(2);
-            BEAST_EXPECT(read_size_helper(sb, 1) == 1);
-            BEAST_EXPECT(read_size_helper(sb, 1000) == 997);
-            BEAST_EXPECT(read_size_helper(sb, 2000) == 997);
-        }
-        {
-            streambuf sb{2};
-            BEAST_EXPECT(sb.alloc_size() == 2);
-            BEAST_EXPECT(test::buffer_count(sb.prepare(2)) == 1);
-            BEAST_EXPECT(test::buffer_count(sb.prepare(3)) == 2);
-            BEAST_EXPECT(buffer_size(sb.prepare(5)) == 5);
-            BEAST_EXPECT(read_size_helper(sb, 10) == 6);
-        }
-        {
-            auto avail =
-                [](streambuf const& sb)
-                {
-                    return sb.capacity() - sb.size();
-                };
-            streambuf sb{100};
-            BEAST_EXPECT(sb.alloc_size() == 100);
-            BEAST_EXPECT(avail(sb) == 0);
-            sb.prepare(100);
-            BEAST_EXPECT(avail(sb) == 100);
-            sb.commit(100);
-            BEAST_EXPECT(avail(sb) == 0);
-            sb.consume(100);
-            BEAST_EXPECT(avail(sb) == 0);
-            sb.alloc_size(200);
-            BEAST_EXPECT(sb.alloc_size() == 200);
-            sb.prepare(1);
-            BEAST_EXPECT(avail(sb) == 200);
-        }
-    }
-
-    void run() override
-    {
-        testSpecialMembers();
-        testAllocator();
-        testPrepare();
-        testCommit();
-        testConsume();
-        testMatrix();
-        testIterators();
-        testOutputStream();
-        testCapacity();
-    }
-};
-
-BEAST_DEFINE_TESTSUITE(basic_streambuf,core,beast);
-
-} // beast
diff --git a/test/core/streambuf.cpp b/test/core/streambuf.cpp
index 3f46658d..815f49c7 100644
--- a/test/core/streambuf.cpp
+++ b/test/core/streambuf.cpp
@@ -8,9 +8,475 @@
 // Test that header file is self-contained.
 #include <beast/core/streambuf.hpp>
 
+#include "buffer_test.hpp"
 #include <beast/core/buffer_concepts.hpp>
+#include <beast/core/to_string.hpp>
+#include <beast/unit_test/suite.hpp>
+#include <boost/asio/buffer.hpp>
+#include <algorithm>
+#include <atomic>
+#include <memory>
+#include <string>
+
 namespace beast {
 
 static_assert(is_DynamicBuffer<streambuf>::value, "");
 
+struct test_allocator_info
+{
+    std::size_t ncopy = 0;
+    std::size_t nmove = 0;
+    std::size_t nselect = 0;
+};
+
+template<class T,
+    bool Assign, bool Move, bool Swap, bool Select>
+class test_allocator;
+
+template<class T,
+    bool Assign, bool Move, bool Swap, bool Select>
+struct test_allocator_base
+{
+};
+
+template<class T,
+    bool Assign, bool Move, bool Swap>
+struct test_allocator_base<T, Assign, Move, Swap, true>
+{
+    static
+    test_allocator<T, Assign, Move, Swap, true>
+    select_on_container_copy_construction(
+        test_allocator<T, Assign, Move, Swap, true> const& a)
+    {
+        return test_allocator<T, Assign, Move, Swap, true>{};
+    }
+};
+
+template<class T,
+    bool Assign, bool Move, bool Swap, bool Select>
+class test_allocator : public test_allocator_base<
+        T, Assign, Move, Swap, Select>
+{
+    std::size_t id_;
+    std::shared_ptr<test_allocator_info> info_;
+
+    template<class, bool, bool, bool, bool>
+    friend class test_allocator;
+
+public:
+    using value_type = T;
+    using propagate_on_container_copy_assignment =
+        std::integral_constant<bool, Assign>;
+    using propagate_on_container_move_assignment =
+        std::integral_constant<bool, Move>;
+    using propagate_on_container_swap =
+        std::integral_constant<bool, Swap>;
+
+    template<class U>
+    struct rebind
+    {
+        using other = test_allocator<
+            U, Assign, Move, Swap, Select>;
+    };
+
+    test_allocator()
+        : id_([]
+            {
+                static std::atomic<
+                    std::size_t> sid(0);
+                return ++sid;
+            }())
+        , info_(std::make_shared<test_allocator_info>())
+    {
+    }
+
+    test_allocator(test_allocator const& u) noexcept
+        : id_(u.id_)
+        , info_(u.info_)
+    {
+        ++info_->ncopy;
+    }
+
+    template<class U>
+    test_allocator(test_allocator<
+            U, Assign, Move, Swap, Select> const& u) noexcept
+        : id_(u.id_)
+        , info_(u.info_)
+    {
+        ++info_->ncopy;
+    }
+
+    test_allocator(test_allocator&& t)
+        : id_(t.id_)
+        , info_(t.info_)
+    {
+        ++info_->nmove;
+    }
+
+    value_type*
+    allocate(std::size_t n)
+    {
+        return static_cast<value_type*>(
+            ::operator new (n*sizeof(value_type)));
+    }
+
+    void
+    deallocate(value_type* p, std::size_t) noexcept
+    {
+        ::operator delete(p);
+    }
+
+    std::size_t
+    id() const
+    {
+        return id_;
+    }
+
+    test_allocator_info const*
+    operator->() const
+    {
+        return info_.get();
+    }
+};
+
+class basic_streambuf_test : public beast::unit_test::suite
+{
+public:
+    template<class Alloc1, class Alloc2>
+    static
+    bool
+    eq(basic_streambuf<Alloc1> const& sb1,
+        basic_streambuf<Alloc2> const& sb2)
+    {
+        return to_string(sb1.data()) == to_string(sb2.data());
+    }
+
+    template<class ConstBufferSequence>
+    void
+    expect_size(std::size_t n, ConstBufferSequence const& buffers)
+    {
+        BEAST_EXPECT(test::size_pre(buffers) == n);
+        BEAST_EXPECT(test::size_post(buffers) == n);
+        BEAST_EXPECT(test::size_rev_pre(buffers) == n);
+        BEAST_EXPECT(test::size_rev_post(buffers) == n);
+    }
+
+    template<class U, class V>
+    static
+    void
+    self_assign(U& u, V&& v)
+    {
+        u = std::forward<V>(v);
+    }
+
+    void testSpecialMembers()
+    {
+        using boost::asio::buffer;
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        std::string const s = "Hello, world";
+        BEAST_EXPECT(s.size() == 12);
+        for(std::size_t i = 1; i < 12; ++i) {
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        std::size_t z = s.size() - (x + y);
+        {
+            streambuf sb(i);
+            sb.commit(buffer_copy(sb.prepare(x), buffer(s.data(), x)));
+            sb.commit(buffer_copy(sb.prepare(y), buffer(s.data()+x, y)));
+            sb.commit(buffer_copy(sb.prepare(z), buffer(s.data()+x+y, z)));
+            BEAST_EXPECT(to_string(sb.data()) == s);
+            {
+                streambuf sb2(sb);
+                BEAST_EXPECT(eq(sb, sb2));
+            }
+            {
+                streambuf sb2;
+                sb2 = sb;
+                BEAST_EXPECT(eq(sb, sb2));
+            }
+            {
+                streambuf sb2(std::move(sb));
+                BEAST_EXPECT(to_string(sb2.data()) == s);
+                expect_size(0, sb.data());
+                sb = std::move(sb2);
+                BEAST_EXPECT(to_string(sb.data()) == s);
+                expect_size(0, sb2.data());
+            }
+            self_assign(sb, sb);
+            BEAST_EXPECT(to_string(sb.data()) == s);
+            self_assign(sb, std::move(sb));
+            BEAST_EXPECT(to_string(sb.data()) == s);
+        }
+        }}}
+        try
+        {
+            streambuf sb0(0);
+            fail();
+        }
+        catch(std::exception const&)
+        {
+            pass();
+        }
+    }
+
+    void testAllocator()
+    {
+        // VFALCO This needs work
+        {
+            using alloc_type =
+                test_allocator<char, false, false, false, false>;
+            using sb_type = basic_streambuf<alloc_type>;
+            sb_type sb;
+            BEAST_EXPECT(sb.get_allocator().id() == 1);
+        }
+        {
+            using alloc_type =
+                test_allocator<char, false, false, false, false>;
+            using sb_type = basic_streambuf<alloc_type>;
+            sb_type sb;
+            BEAST_EXPECT(sb.get_allocator().id() == 2);
+            sb_type sb2(sb);
+            BEAST_EXPECT(sb2.get_allocator().id() == 2);
+            sb_type sb3(sb, alloc_type{});
+        }
+    }
+
+    void
+    testPrepare()
+    {
+        using boost::asio::buffer_size;
+        {
+            streambuf sb(2);
+            BEAST_EXPECT(buffer_size(sb.prepare(5)) == 5);
+            BEAST_EXPECT(buffer_size(sb.prepare(8)) == 8);
+            BEAST_EXPECT(buffer_size(sb.prepare(7)) == 7);
+        }
+        {
+            streambuf sb(2);
+            sb.prepare(2);
+            BEAST_EXPECT(test::buffer_count(sb.prepare(5)) == 2);
+            BEAST_EXPECT(test::buffer_count(sb.prepare(8)) == 3);
+            BEAST_EXPECT(test::buffer_count(sb.prepare(4)) == 2);
+        }
+    }
+
+    void testCommit()
+    {
+        using boost::asio::buffer_size;
+        streambuf sb(2);
+        sb.prepare(2);
+        sb.prepare(5);
+        sb.commit(1);
+        expect_size(1, sb.data());
+    }
+
+    void testConsume()
+    {
+        using boost::asio::buffer_size;
+        streambuf sb(1);
+        expect_size(5, sb.prepare(5));
+        sb.commit(3);
+        expect_size(3, sb.data());
+        sb.consume(1);
+        expect_size(2, sb.data());
+    }
+
+    void testMatrix()
+    {
+        using boost::asio::buffer;
+        using boost::asio::buffer_cast;
+        using boost::asio::buffer_size;
+        std::string const s = "Hello, world";
+        BEAST_EXPECT(s.size() == 12);
+        for(std::size_t i = 1; i < 12; ++i) {
+        for(std::size_t x = 1; x < 4; ++x) {
+        for(std::size_t y = 1; y < 4; ++y) {
+        for(std::size_t t = 1; t < 4; ++ t) {
+        for(std::size_t u = 1; u < 4; ++ u) {
+        std::size_t z = s.size() - (x + y);
+        std::size_t v = s.size() - (t + u);
+        {
+            streambuf sb(i);
+            {
+                auto d = sb.prepare(z);
+                BEAST_EXPECT(buffer_size(d) == z);
+            }
+            {
+                auto d = sb.prepare(0);
+                BEAST_EXPECT(buffer_size(d) == 0);
+            }
+            {
+                auto d = sb.prepare(y);
+                BEAST_EXPECT(buffer_size(d) == y);
+            }
+            {
+                auto d = sb.prepare(x);
+                BEAST_EXPECT(buffer_size(d) == x);
+                sb.commit(buffer_copy(d, buffer(s.data(), x)));
+            }
+            BEAST_EXPECT(sb.size() == x);
+            BEAST_EXPECT(buffer_size(sb.data()) == sb.size());
+            {
+                auto d = sb.prepare(x);
+                BEAST_EXPECT(buffer_size(d) == x);
+            }
+            {
+                auto d = sb.prepare(0);
+                BEAST_EXPECT(buffer_size(d) == 0);
+            }
+            {
+                auto d = sb.prepare(z);
+                BEAST_EXPECT(buffer_size(d) == z);
+            }
+            {
+                auto d = sb.prepare(y);
+                BEAST_EXPECT(buffer_size(d) == y);
+                sb.commit(buffer_copy(d, buffer(s.data()+x, y)));
+            }
+            sb.commit(1);
+            BEAST_EXPECT(sb.size() == x + y);
+            BEAST_EXPECT(buffer_size(sb.data()) == sb.size());
+            {
+                auto d = sb.prepare(x);
+                BEAST_EXPECT(buffer_size(d) == x);
+            }
+            {
+                auto d = sb.prepare(y);
+                BEAST_EXPECT(buffer_size(d) == y);
+            }
+            {
+                auto d = sb.prepare(0);
+                BEAST_EXPECT(buffer_size(d) == 0);
+            }
+            {
+                auto d = sb.prepare(z);
+                BEAST_EXPECT(buffer_size(d) == z);
+                sb.commit(buffer_copy(d, buffer(s.data()+x+y, z)));
+            }
+            sb.commit(2);
+            BEAST_EXPECT(sb.size() == x + y + z);
+            BEAST_EXPECT(buffer_size(sb.data()) == sb.size());
+            BEAST_EXPECT(to_string(sb.data()) == s);
+            sb.consume(t);
+            {
+                auto d = sb.prepare(0);
+                BEAST_EXPECT(buffer_size(d) == 0);
+            }
+            BEAST_EXPECT(to_string(sb.data()) == s.substr(t, std::string::npos));
+            sb.consume(u);
+            BEAST_EXPECT(to_string(sb.data()) == s.substr(t + u, std::string::npos));
+            sb.consume(v);
+            BEAST_EXPECT(to_string(sb.data()) == "");
+            sb.consume(1);
+            {
+                auto d = sb.prepare(0);
+                BEAST_EXPECT(buffer_size(d) == 0);
+            }
+        }
+        }}}}}
+    }
+
+    void testIterators()
+    {
+        using boost::asio::buffer_size;
+        streambuf sb(1);
+        sb.prepare(1);
+        sb.commit(1);
+        sb.prepare(2);
+        sb.commit(2);
+        expect_size(3, sb.data());
+        sb.prepare(1);
+        expect_size(3, sb.prepare(3));
+        sb.commit(2);
+        BEAST_EXPECT(test::buffer_count(sb.data()) == 4);
+    }
+
+    void testOutputStream()
+    {
+        streambuf sb;
+        sb << "x";
+        BEAST_EXPECT(to_string(sb.data()) == "x");
+    }
+
+    void testCapacity()
+    {
+        using boost::asio::buffer_size;
+        {
+            streambuf sb{10};
+            BEAST_EXPECT(sb.alloc_size() == 10);
+            BEAST_EXPECT(read_size_helper(sb, 1) == 1);
+            BEAST_EXPECT(read_size_helper(sb, 10) == 10);
+            BEAST_EXPECT(read_size_helper(sb, 20) == 20);
+            BEAST_EXPECT(read_size_helper(sb, 1000) == 512);
+            sb.prepare(3);
+            sb.commit(3);
+            BEAST_EXPECT(read_size_helper(sb, 10) == 7);
+            BEAST_EXPECT(read_size_helper(sb, 1000) == 7);
+        }
+        {
+            streambuf sb(1000);
+            BEAST_EXPECT(sb.alloc_size() == 1000);
+            BEAST_EXPECT(read_size_helper(sb, 1) == 1);
+            BEAST_EXPECT(read_size_helper(sb, 1000) == 1000);
+            BEAST_EXPECT(read_size_helper(sb, 2000) == 1000);
+            sb.prepare(3);
+            BEAST_EXPECT(read_size_helper(sb, 1) == 1);
+            BEAST_EXPECT(read_size_helper(sb, 1000) == 1000);
+            BEAST_EXPECT(read_size_helper(sb, 2000) == 1000);
+            sb.commit(3);
+            BEAST_EXPECT(read_size_helper(sb, 1) == 1);
+            BEAST_EXPECT(read_size_helper(sb, 1000) == 997);
+            BEAST_EXPECT(read_size_helper(sb, 2000) == 997);
+            sb.consume(2);
+            BEAST_EXPECT(read_size_helper(sb, 1) == 1);
+            BEAST_EXPECT(read_size_helper(sb, 1000) == 997);
+            BEAST_EXPECT(read_size_helper(sb, 2000) == 997);
+        }
+        {
+            streambuf sb{2};
+            BEAST_EXPECT(sb.alloc_size() == 2);
+            BEAST_EXPECT(test::buffer_count(sb.prepare(2)) == 1);
+            BEAST_EXPECT(test::buffer_count(sb.prepare(3)) == 2);
+            BEAST_EXPECT(buffer_size(sb.prepare(5)) == 5);
+            BEAST_EXPECT(read_size_helper(sb, 10) == 6);
+        }
+        {
+            auto avail =
+                [](streambuf const& sb)
+                {
+                    return sb.capacity() - sb.size();
+                };
+            streambuf sb{100};
+            BEAST_EXPECT(sb.alloc_size() == 100);
+            BEAST_EXPECT(avail(sb) == 0);
+            sb.prepare(100);
+            BEAST_EXPECT(avail(sb) == 100);
+            sb.commit(100);
+            BEAST_EXPECT(avail(sb) == 0);
+            sb.consume(100);
+            BEAST_EXPECT(avail(sb) == 0);
+            sb.alloc_size(200);
+            BEAST_EXPECT(sb.alloc_size() == 200);
+            sb.prepare(1);
+            BEAST_EXPECT(avail(sb) == 200);
+        }
+    }
+
+    void run() override
+    {
+        testSpecialMembers();
+        testAllocator();
+        testPrepare();
+        testCommit();
+        testConsume();
+        testMatrix();
+        testIterators();
+        testOutputStream();
+        testCapacity();
+    }
+};
+
+BEAST_DEFINE_TESTSUITE(basic_streambuf,core,beast);
+
 } // beast