diff --git a/build/ipc.pro b/build/ipc.pro
index 652f270..8a0370c 100644
--- a/build/ipc.pro
+++ b/build/ipc.pro
@@ -25,6 +25,7 @@ HEADERS += \
     ../include/rw_lock.h \
     ../include/tls_pointer.h \
     ../include/pool_alloc.h \
+    ../include/buffer.h \
     ../src/channel.inc \
     ../src/route.inc \
     ../src/id_pool.inc \
@@ -35,7 +36,8 @@ HEADERS += \
 SOURCES += \
     ../src/shm.cpp \
     ../src/ipc.cpp \
-    ../src/pool_alloc.cpp
+    ../src/pool_alloc.cpp \
+    ../src/buffer.cpp
 
 unix {
 
diff --git a/include/buffer.h b/include/buffer.h
new file mode 100644
index 0000000..1835ba5
--- /dev/null
+++ b/include/buffer.h
@@ -0,0 +1,63 @@
+#pragma once
+
+#include <cstddef>
+#include <tuple>
+#include <vector>
+
+#include "export.h"
+#include "def.h"
+
+namespace ipc {
+
+class IPC_EXPORT buffer {
+public:
+    using destructor_t = void (*)(void*, std::size_t);
+
+    buffer();
+
+    buffer(void* p, std::size_t s, destructor_t d);
+    buffer(void* p, std::size_t s);
+
+    template <std::size_t N>
+    explicit buffer(byte_t const (& data)[N])
+        : buffer(data, sizeof(data)) {
+    }
+    explicit buffer(char const & c);
+
+    buffer(buffer&& rhs);
+    ~buffer();
+
+    void swap(buffer& rhs);
+    buffer& operator=(buffer rhs);
+
+    bool empty() const noexcept;
+
+    void *       data()       noexcept;
+    void const * data() const noexcept;
+
+    std::size_t size() const noexcept;
+
+    std::tuple<void*, std::size_t> to_tuple() {
+        return std::make_tuple(data(), size());
+    }
+
+    std::tuple<void const *, std::size_t> to_tuple() const {
+        return std::make_tuple(data(), size());
+    }
+
+    std::vector<byte_t> to_vector() const {
+        auto [d, s] = to_tuple();
+        return {
+            static_cast<byte_t const *>(d),
+            static_cast<byte_t const *>(d) + s
+        };
+    }
+
+    friend IPC_EXPORT bool operator==(buffer const & b1, buffer const & b2);
+
+private:
+    class buffer_;
+    buffer_* p_;
+};
+
+} // namespace ipc
diff --git a/include/ipc.h b/include/ipc.h
index 2036e7d..43b189c 100644
--- a/include/ipc.h
+++ b/include/ipc.h
@@ -5,17 +5,13 @@
 
 #include "export.h"
 #include "def.h"
+#include "buffer.h"
 #include "shm.h"
 
 namespace ipc {
 
 using handle_t = void*;
-using buff_t   = std::vector<byte_t>;
-
-IPC_EXPORT buff_t make_buff(void const * data, std::size_t size);
-
-template <std::size_t N>
-buff_t make_buff(byte_t const (& data)[N]) { return make_buff(data, N); }
+using buff_t   = buffer;
 
 IPC_EXPORT handle_t connect   (char const * name);
 IPC_EXPORT void     disconnect(handle_t h);
diff --git a/src/buffer.cpp b/src/buffer.cpp
new file mode 100644
index 0000000..1625c5b
--- /dev/null
+++ b/src/buffer.cpp
@@ -0,0 +1,77 @@
+#include "buffer.h"
+
+#include <cstring>
+
+namespace ipc {
+
+bool operator==(buffer const & b1, buffer const & b2) {
+    return (b1.size() == b2.size()) && (std::memcmp(b1.data(), b2.data(), b1.size()) == 0);
+}
+
+class buffer::buffer_ : public pimpl<buffer_> {
+public:
+    void*        p_;
+    std::size_t  s_;
+    destructor_t d_;
+
+    buffer_(void* p, std::size_t s, destructor_t d)
+        : p_(p), s_(s), d_(d) {
+    }
+
+    ~buffer_() {
+        if (d_ == nullptr) return;
+        d_(p_, s_);
+    }
+};
+
+buffer::buffer()
+    : buffer(nullptr, 0, nullptr) {
+}
+
+buffer::buffer(void* p, std::size_t s, destructor_t d)
+    : p_(p_->make(p, s, d)) {
+}
+
+buffer::buffer(void* p, std::size_t s)
+    : buffer(p, s, nullptr) {
+}
+
+buffer::buffer(char const & c)
+    : buffer(const_cast<char*>(&c), 1, nullptr) {
+}
+
+buffer::buffer(buffer&& rhs)
+    : p_(nullptr) {
+    swap(rhs);
+}
+
+buffer::~buffer() {
+    p_->clear();
+}
+
+void buffer::swap(buffer& rhs) {
+    std::swap(p_, rhs.p_);
+}
+
+buffer& buffer::operator=(buffer rhs) {
+    swap(rhs);
+    return *this;
+}
+
+bool buffer::empty() const noexcept {
+    return (impl(p_)->p_ == nullptr) || (impl(p_)->s_ == 0);
+}
+
+void* buffer::data() noexcept {
+    return impl(p_)->p_;
+}
+
+void const * buffer::data() const noexcept {
+    return impl(p_)->p_;
+}
+
+std::size_t buffer::size() const noexcept {
+    return impl(p_)->s_;
+}
+
+} // namespace ipc
diff --git a/src/ipc.cpp b/src/ipc.cpp
index 2a90285..3490b55 100644
--- a/src/ipc.cpp
+++ b/src/ipc.cpp
@@ -46,28 +46,25 @@ constexpr queue_t* queue_of(handle_t h) {
     return static_cast<queue_t*>(h);
 }
 
-using cache_t = mem::vector<byte_t>;
-
-template <std::size_t N>
-cache_t make_cache(byte_t const (& data)[N]) {
-    return {
-        static_cast<cache_t::value_type const *>(data),
-        static_cast<cache_t::value_type const *>(data) + N
-    };
+inline buff_t make_cache(void const * data, std::size_t size) {
+    auto ptr = mem::detail::pool_alloc::alloc(size);
+    std::memcpy(ptr, data, size);
+    return { ptr, size, mem::detail::pool_alloc::free };
 }
 
-template <typename T>
-using remove_cv_ref_t = std::remove_cv_t<std::remove_reference_t<T>>;
+struct cache_t {
+    std::size_t fill_;
+    buff_t      buff_;
 
-template <typename Cache>
-constexpr auto to_buff(Cache&& cac) -> Requires<std::is_same<remove_cv_ref_t<Cache>, buff_t>::value, Cache&&> {
-    return std::forward<Cache>(cac);
-}
+    cache_t(std::size_t f, buff_t&& b)
+        : fill_(f), buff_(std::move(b))
+    {}
 
-template <typename Cache>
-auto to_buff(Cache&& cac) -> Requires<!std::is_same<remove_cv_ref_t<Cache>, buff_t>::value, buff_t> {
-    return make_buff(cac.data(), cac.size());
-}
+    void append(void const * data, std::size_t size) {
+        std::memcpy(static_cast<byte_t*>(buff_.data()) + fill_, data, size);
+        fill_ += size;
+    }
+};
 
 inline auto& recv_cache() {
     /*
@@ -92,13 +89,6 @@ inline auto& queues_cache() {
 
 namespace ipc {
 
-buff_t make_buff(void const * data, std::size_t size) {
-    return {
-        static_cast<buff_t::value_type const *>(data),
-        static_cast<buff_t::value_type const *>(data) + size
-    };
-}
-
 handle_t connect(char const * name) {
     auto mem = shm::acquire(name, sizeof(shm_info_t));
     if (mem == nullptr) {
@@ -185,27 +175,27 @@ buff_t multi_recv(F&& upd) {
         std::size_t remain = static_cast<std::size_t>(
                              static_cast<int>(data_length) + msg.remain_);
         // find cache with msg.id_
-        auto cache_it = rc.find(msg.id_);
-        if (cache_it == rc.end()) {
+        auto cac_it = rc.find(msg.id_);
+        if (cac_it == rc.end()) {
             if (remain <= data_length) {
-                return make_buff(msg.data_, remain);
+                return make_cache(msg.data_, remain);
             }
             // cache the first message fragment
-            else rc.emplace(msg.id_, make_cache(msg.data_));
+            else rc.try_emplace(msg.id_, data_length, make_cache(msg.data_, remain));
         }
         // has cached before this message
         else {
-            auto& cache = cache_it->second;
+            auto& cac = cac_it->second;
             // this is the last message fragment
             if (msg.remain_ <= 0) {
-                cache.insert(cache.end(), msg.data_, msg.data_ + remain);
+                cac.append(msg.data_, remain);
                 // finish this message, erase it from cache
-                auto cac = std::move(cache);
-                rc.erase(cache_it);
-                return to_buff(std::move(cac));
+                auto buff = std::move(cac.buff_);
+                rc.erase(cac_it);
+                return buff;
             }
             // there are remain datas after this message
-            cache.insert(cache.end(), msg.data_, msg.data_ + data_length);
+            cac.append(msg.data_, data_length);
         }
     }
 }
diff --git a/test/test_ipc.cpp b/test/test_ipc.cpp
index 9c18e62..04a86ea 100644
--- a/test/test_ipc.cpp
+++ b/test/test_ipc.cpp
@@ -42,14 +42,18 @@ struct test_verify {
 
     void prepare(void* /*pt*/) {}
 
-    void push_data(int cid, ipc::buff_t const & msg) {
+    void push_data(int cid, ipc::buff_t & msg) {
         list_[cid].emplace_back(std::move(msg));
     }
 
     void verify(int /*N*/, int /*Loops*/) {
         std::cout << "verifying..." << std::endl;
         for (auto& c_dats : list_) {
-            QCOMPARE(datas__, c_dats);
+            QCOMPARE(datas__.size(), c_dats.size());
+            std::size_t i = 0;
+            for (auto& d : c_dats) {
+                QCOMPARE(datas__[i++], d);
+            }
         }
     }
 };
@@ -85,7 +89,7 @@ struct test_cq<ipc::route> {
         do {
             auto msg = cn.recv();
             if (msg.size() < 2) {
-                QCOMPARE(msg, ipc::buff_t { '\0' });
+                QCOMPARE(msg, ipc::buff_t('\0'));
                 return;
             }
             proc(msg);
@@ -99,7 +103,7 @@ struct test_cq<ipc::route> {
     void send(cn_t& cn, const std::array<int, 2>& info) {
         int n = info[1];
         if (n < 0) {
-            /*QVERIFY*/(cn.send(ipc::buff_t { '\0' }));
+            /*QVERIFY*/(cn.send(ipc::buff_t('\0')));
         }
         else /*QVERIFY*/(cn.send(datas__[static_cast<decltype(datas__)::size_type>(n)]));
     }
@@ -137,7 +141,7 @@ struct test_cq<ipc::channel> {
         do {
             auto msg = cn.recv();
             if (msg.size() < 2) {
-                QCOMPARE(msg, ipc::buff_t { '\0' });
+                QCOMPARE(msg, ipc::buff_t('\0'));
                 return;
             }
             proc(msg);
@@ -162,7 +166,7 @@ struct test_cq<ipc::channel> {
         } _(cn, m_);
         int n = info[1];
         if (n < 0) {
-            /*QVERIFY*/(cn->send(ipc::buff_t { '\0' }));
+            /*QVERIFY*/(cn->send(ipc::buff_t('\0')));
         }
         else /*QVERIFY*/(cn->send(datas__[static_cast<decltype(datas__)::size_type>(n)]));
     }
@@ -197,13 +201,18 @@ void Unit::initTestCase() {
     TestSuite::initTestCase();
 
     capo::random<> rdm { DataMin, DataMax };
-    capo::random<> bit { 0, (std::numeric_limits<ipc::buff_t::value_type>::max)() };
+    capo::random<> bit { 0, (std::numeric_limits<ipc::byte_t>::max)() };
 
     for (int i = 0; i < LoopCount; ++i) {
-        auto n = rdm();
-        ipc::buff_t buff(static_cast<ipc::buff_t::size_type>(n));
+        std::size_t n = static_cast<std::size_t>(rdm());
+        ipc::buff_t buff {
+            new ipc::byte_t[n], n,
+            [](void* p, std::size_t) {
+                delete [] static_cast<ipc::byte_t*>(p);
+            }
+        };
         for (std::size_t k = 0; k < buff.size(); ++k) {
-            buff[k] = static_cast<ipc::buff_t::value_type>(bit());
+            static_cast<ipc::byte_t*>(buff.data())[k] = static_cast<ipc::byte_t>(bit());
         }
         datas__.emplace_back(std::move(buff));
     }
@@ -381,7 +390,7 @@ void Unit::test_route_rtt() {
             auto dd = cc.recv();
             if (dd.size() < 2) return;
 //            std::cout << "recving: " << i << "-[" << dd.size() << "]" << std::endl;
-            while (!cr.send(ipc::buff_t { 'a' })) {
+            while (!cr.send(ipc::buff_t('a'))) {
                 std::this_thread::yield();
             }
         }
@@ -402,7 +411,7 @@ void Unit::test_route_rtt() {
 //                QVERIFY(false);
 //            }
         }
-        cc.send(ipc::buff_t { '\0' });
+        cc.send(ipc::buff_t('\0'));
         t1.join();
         sw.print_elapsed(1, 1, LoopCount);
     }};
@@ -466,7 +475,7 @@ void Unit::test_channel() {
             std::cout << "sending: " << i << "-[" << datas__[i].size() << "]" << std::endl;
             cc.send(datas__[i]);
         }
-        cc.send(ipc::buff_t { '\0' });
+        cc.send(ipc::buff_t('\0'));
         t1.join();
     }};
 
@@ -482,7 +491,7 @@ void Unit::test_channel_rtt() {
             auto dd = cc.recv();
             if (dd.size() < 2) return;
 //            std::cout << "recving: " << i << "-[" << dd.size() << "]" << std::endl;
-            while (!cc.send(ipc::buff_t { 'a' })) {
+            while (!cc.send(ipc::buff_t('a'))) {
                 cc.wait_for_recv(1);
             }
         }
@@ -500,7 +509,7 @@ void Unit::test_channel_rtt() {
 //                QVERIFY(false);
 //            }
         }
-        cc.send(ipc::buff_t { '\0' });
+        cc.send(ipc::buff_t('\0'));
         t1.join();
         sw.print_elapsed(1, 1, LoopCount);
     }};