diff --git a/examples/0037.ipc/.test_prop.toml b/examples/0037.ipc/.test_prop.toml
deleted file mode 100644
index 6e3ff797e..000000000
--- a/examples/0037.ipc/.test_prop.toml
+++ /dev/null
@@ -1,7 +0,0 @@
-["win32_named_pipe"]
-interactive = true
-platform = "windows"
-
-["nt_alpc"]
-ignore = true
-platform = "windows"
diff --git a/examples/0037.ipc/nt_alpc/client.cc b/examples/0037.ipc/nt_alpc/client.cc
deleted file mode 100644
index 9e1625484..000000000
--- a/examples/0037.ipc/nt_alpc/client.cc
+++ /dev/null
@@ -1,24 +0,0 @@
-#include <fast_io.h>
-#include <fast_io_device.h>
-#include <fast_io_dsal/string.h>
-
-int main()
-{
-	try
-	{
-		::fast_io::io::perrln("client -> connect -> server: ", "try to connect");
-		::fast_io::basic_nt_family_alpc_ipc_client<::fast_io::nt_family::nt, char> c{"test", ::fast_io::ipc_mode::out, "try to connect!\n"};
-		::fast_io::basic_ibuf<::fast_io::basic_nt_family_alpc_ipc_client_observer<::fast_io::nt_family::nt, char>> c_buf{c};
-
-		::fast_io::string str{};
-		::fast_io::io::scan(c_buf, ::fast_io::mnp::line_get(str));
-		::fast_io::io::perrln("server -> accept -> client: ", str);
-
-		::fast_io::io::scan(c_buf, ::fast_io::mnp::line_get(str));
-		::fast_io::io::perrln("client -> recv -> server ", str);
-	}
-	catch (::fast_io::error e)
-	{
-		::fast_io::io::perrln(e);
-	}
-}
diff --git a/examples/0037.ipc/nt_alpc/server.cc b/examples/0037.ipc/nt_alpc/server.cc
deleted file mode 100644
index 6fd27d110..000000000
--- a/examples/0037.ipc/nt_alpc/server.cc
+++ /dev/null
@@ -1,31 +0,0 @@
-#include <fast_io.h>
-#include <fast_io_device.h>
-#include <fast_io_dsal/string.h>
-
-int main(int argc, char **argv)
-{
-	try
-	{
-		::fast_io::io::perrln("server create: ", "test");
-		::fast_io::basic_nt_family_alpc_ipc_server<::fast_io::nt_family::nt, char> s{"test", ::fast_io::ipc_mode::in};
-		::fast_io::basic_ibuf<::fast_io::basic_nt_family_alpc_ipc_server_observer<::fast_io::nt_family::nt, char>> s_buf{s};
-
-		auto c{wait_for_connect(s)};
-		::fast_io::string str{};
-		::fast_io::io::scan(s_buf, ::fast_io::mnp::line_get(str));
-		::fast_io::io::perrln("client -> connect -> server: ", str);
-
-		::fast_io::io::perrln("server -> accept -> client: ", "good");
-
-		::fast_io::io::print(s, "good\n");
-		accept_connect(s, c, true);
-
-		::fast_io::io::perrln("server -> send -> client: ", "hello");
-		::fast_io::io::print(s, "hello\n");
-	}
-	catch (::fast_io::error e)
-	{
-		::fast_io::io::perrln(e);
-	}
-
-}
diff --git a/examples/0037.ipc/win32_named_pipe/client_receiver.cc b/examples/0037.ipc/win32_named_pipe/client_receiver.cc
deleted file mode 100644
index e23356bd6..000000000
--- a/examples/0037.ipc/win32_named_pipe/client_receiver.cc
+++ /dev/null
@@ -1,26 +0,0 @@
-#include <fast_io.h>
-#include <fast_io_device.h>
-#include <fast_io_dsal/string.h>
-
-int main()
-{
-	try
-	{
-		::fast_io::io::print(::fast_io::u8out(), u8"connect to win32 named pipe server sender!\nserver name: ");
-		::fast_io::u8string pipe_name{};
-		::fast_io::scan(::fast_io::u8c_stdin(), ::fast_io::mnp::line_get(pipe_name));
-		::fast_io::u8win32_named_pipe_ipc_client s{pipe_name, ::fast_io::ipc_mode::in};
-		::fast_io::basic_ibuf<::fast_io::u8win32_named_pipe_ipc_client_observer> s_ibuf{s};
-		::fast_io::io::print(::fast_io::u8out(), u8"connected!\n");
-		for (;;)
-		{
-			::fast_io::u8string str_name{};
-			::fast_io::scan(s_ibuf, ::fast_io::mnp::line_get(str_name));
-			::fast_io::println(::fast_io::u8out(), str_name);
-		}
-	}
-	catch (::fast_io::error e)
-	{
-		::fast_io::io::perrln(e);
-	}
-}
diff --git a/examples/0037.ipc/win32_named_pipe/server_sender.cc b/examples/0037.ipc/win32_named_pipe/server_sender.cc
deleted file mode 100644
index bfa698098..000000000
--- a/examples/0037.ipc/win32_named_pipe/server_sender.cc
+++ /dev/null
@@ -1,30 +0,0 @@
-#include <fast_io.h>
-#include <fast_io_device.h>
-#include <fast_io_dsal/string.h>
-
-int main()
-{
-	try
-	{
-		::fast_io::io::print(::fast_io::u8out(), u8"create win32 named pipe server sender!\nserver name: ");
-		::fast_io::u8string pipe_name{};
-		::fast_io::scan(::fast_io::u8c_stdin(), ::fast_io::mnp::line_get(pipe_name));
-		::fast_io::u8win32_named_pipe_ipc_server s{pipe_name, ::fast_io::ipc_mode::out};
-		::fast_io::basic_obuf<::fast_io::u8win32_named_pipe_ipc_server> s_obuf{s};
-		::fast_io::io::print(::fast_io::u8out(), u8"wait for connect\n");
-		wait_for_connect(s);
-		::fast_io::io::print(::fast_io::u8out(), u8"connected!\n");
-		for (;;)
-		{
-			::fast_io::u8string str_name{};
-			::fast_io::io::print(::fast_io::u8out(), u8"send: ");
-			::fast_io::scan(::fast_io::u8c_stdin(), ::fast_io::mnp::line_get(str_name));
-			::fast_io::println(s_obuf, str_name);
-			::fast_io::details::close_basic_io_buffer(s_obuf);
-		}
-	}
-	catch (::fast_io::error e)
-	{
-		::fast_io::io::perrln(e);
-	}
-}
diff --git a/include/fast_io_core.h b/include/fast_io_core.h
index 5baeecc5b..4cfee0287 100644
--- a/include/fast_io_core.h
+++ b/include/fast_io_core.h
@@ -64,8 +64,6 @@
 // #include"fast_io_core_impl/manip/impl.h"
 #include "fast_io_core_impl/mode.h"
 #include "fast_io_core_impl/perms.h"
-#include "fast_io_dsal/impl/common.h"
-#include "fast_io_dsal/impl/span.h"
 #include "fast_io_core_impl/operations/impl.h"
 
 // This should provide an option macro to disable any generation for table in freestanding environments.
diff --git a/include/fast_io_core_impl/operations/readimpl/impl.h b/include/fast_io_core_impl/operations/readimpl/impl.h
index 575ca172c..e67109b7e 100644
--- a/include/fast_io_core_impl/operations/readimpl/impl.h
+++ b/include/fast_io_core_impl/operations/readimpl/impl.h
@@ -7,5 +7,4 @@
 #include "scatterp.h"
 #include "scatterpbytes.h"
 #include "decay.h"
-#include "spanops.h"
 #include "ptrops.h"
diff --git a/include/fast_io_core_impl/operations/readimpl/spanops.h b/include/fast_io_core_impl/operations/readimpl/spanops.h
deleted file mode 100644
index dbab9b9c3..000000000
--- a/include/fast_io_core_impl/operations/readimpl/spanops.h
+++ /dev/null
@@ -1,192 +0,0 @@
-#pragma once
-
-
-namespace fast_io::operations
-{
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr ::fast_io::containers::span<char_type> read_some_span(outstmtype &&outstm, ::fast_io::containers::span<char_type> sp)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	return ::fast_io::containers::span<char_type>(first, ::fast_io::details::read_some_impl(::fast_io::operations::input_stream_ref(outstm), first, last));
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr void read_all_span(outstmtype &&outstm, ::fast_io::containers::span<char_type> sp)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	::fast_io::details::read_some_impl(::fast_io::operations::input_stream_ref(outstm), first, last);
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr ::fast_io::containers::span<::std::byte const> read_some_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::std::byte const> sp)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	return ::fast_io::containers::span<::std::byte const>(first, ::fast_io::details::read_some_bytes_impl(::fast_io::operations::input_stream_ref(outstm), first, last));
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr void read_all_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::std::byte const> sp)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	::fast_io::details::read_all_bytes_impl(::fast_io::operations::input_stream_ref(outstm), first, last);
-}
-
-template <typename outstmtype>
-inline constexpr io_scatter_status_t scatter_read_some_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::io_scatter_t const> sp)
-{
-	using io_scatter_may_alias_const_ptr
-#if __has_cpp_attribute(__gnu__::__may_alias__)
-		[[__gnu__::__may_alias__]]
-#endif
-		= io_scatter_t const *;
-	return ::fast_io::details::scatter_read_some_bytes_impl(::fast_io::operations::input_stream_ref(outstm),
-															 reinterpret_cast<io_scatter_may_alias_const_ptr>(sp.data()),
-															 sp.size());
-}
-
-template <typename outstmtype>
-inline constexpr void scatter_read_all_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::io_scatter_t const> sp)
-{
-	using io_scatter_may_alias_const_ptr
-#if __has_cpp_attribute(__gnu__::__may_alias__)
-		[[__gnu__::__may_alias__]]
-#endif
-		= io_scatter_t const *;
-	::fast_io::details::scatter_read_all_bytes_impl(::fast_io::operations::input_stream_ref(outstm),
-													 reinterpret_cast<io_scatter_may_alias_const_ptr>(sp.data()),
-													 sp.size());
-}
-
-template <typename outstmtype>
-inline constexpr io_scatter_status_t scatter_read_some_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::basic_io_scatter_t<typename decltype(::fast_io::operations::input_stream_ref(outstm))::input_char_type> const> sp)
-{
-	using io_scatter_may_alias_const_ptr
-#if __has_cpp_attribute(__gnu__::__may_alias__)
-		[[__gnu__::__may_alias__]]
-#endif
-		= basic_io_scatter_t<typename decltype(::fast_io::operations::input_stream_ref(outstm))::input_char_type> const *;
-	return ::fast_io::details::scatter_read_some_impl(::fast_io::operations::input_stream_ref(outstm),
-													   reinterpret_cast<io_scatter_may_alias_const_ptr>(sp.data()),
-													   sp.size());
-}
-
-template <typename outstmtype>
-inline constexpr void scatter_read_all_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::basic_io_scatter_t<typename decltype(::fast_io::operations::input_stream_ref(outstm))::input_char_type> const> sp)
-{
-	using io_scatter_may_alias_const_ptr
-#if __has_cpp_attribute(__gnu__::__may_alias__)
-		[[__gnu__::__may_alias__]]
-#endif
-		= basic_io_scatter_t<typename decltype(::fast_io::operations::input_stream_ref(outstm))::input_char_type> const *;
-	::fast_io::details::scatter_read_all_impl(::fast_io::operations::input_stream_ref(outstm),
-											   reinterpret_cast<io_scatter_may_alias_const_ptr>(sp.data()),
-											   sp.size());
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr ::fast_io::containers::span<char_type> pread_some_span(outstmtype &&outstm, ::fast_io::containers::span<char_type> sp, ::fast_io::intfpos_t off)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	return ::fast_io::containers::span<char_type>(first, ::fast_io::details::pread_some_impl(::fast_io::operations::input_stream_ref(outstm), first, last, off));
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr void pread_all_span(outstmtype &&outstm, ::fast_io::containers::span<char_type> sp, ::fast_io::intfpos_t off)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	::fast_io::details::pread_all_impl(::fast_io::operations::input_stream_ref(outstm), first, last, off);
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr ::fast_io::containers::span<::std::byte const> pread_some_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::std::byte const> sp, ::fast_io::intfpos_t off)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	return ::fast_io::containers::span<::std::byte const>(first, ::fast_io::details::pread_some_bytes_impl(::fast_io::operations::input_stream_ref(outstm), first, last, off));
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr void pread_all_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::std::byte const> sp, ::fast_io::intfpos_t off)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	::fast_io::details::pread_all_bytes_impl(::fast_io::operations::input_stream_ref(outstm), first, last, off);
-}
-
-template <typename outstmtype>
-inline constexpr io_scatter_status_t scatter_pread_some_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::io_scatter_t const> sp, ::fast_io::intfpos_t off)
-{
-
-	return ::fast_io::details::scatter_pread_some_bytes_impl(::fast_io::operations::input_stream_ref(outstm),
-															  sp.data(), sp.size(), off);
-}
-
-template <typename outstmtype>
-inline constexpr void scatter_pread_all_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::io_scatter_t const> sp, ::fast_io::intfpos_t off)
-{
-	::fast_io::details::scatter_pread_all_bytes_impl(::fast_io::operations::input_stream_ref(outstm),
-													  sp.data(), sp.size(), off);
-}
-
-template <typename outstmtype>
-inline constexpr io_scatter_status_t scatter_pread_some_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::basic_io_scatter_t<typename decltype(::fast_io::operations::input_stream_ref(outstm))::input_char_type> const> sp, ::fast_io::intfpos_t off)
-{
-	return ::fast_io::details::scatter_pread_some_impl(::fast_io::operations::input_stream_ref(outstm),
-														sp.data(), sp.size(), off);
-}
-
-template <typename outstmtype>
-inline constexpr void scatter_pread_all_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::basic_io_scatter_t<typename decltype(::fast_io::operations::input_stream_ref(outstm))::input_char_type> const> sp, ::fast_io::intfpos_t off)
-{
-
-	::fast_io::details::scatter_pread_all_impl(::fast_io::operations::input_stream_ref(outstm), sp.data(), sp.size(), off);
-}
-
-} // namespace fast_io::operations
diff --git a/include/fast_io_core_impl/operations/writeimpl/impl.h b/include/fast_io_core_impl/operations/writeimpl/impl.h
index 26a0644a6..2b6d71ab3 100644
--- a/include/fast_io_core_impl/operations/writeimpl/impl.h
+++ b/include/fast_io_core_impl/operations/writeimpl/impl.h
@@ -8,5 +8,4 @@
 #include "scatterpbytes.h"
 #include "decay.h"
 #include "range.h"
-#include "spanops.h"
 #include "ptrops.h"
diff --git a/include/fast_io_core_impl/operations/writeimpl/spanops.h b/include/fast_io_core_impl/operations/writeimpl/spanops.h
deleted file mode 100644
index f6d37c875..000000000
--- a/include/fast_io_core_impl/operations/writeimpl/spanops.h
+++ /dev/null
@@ -1,192 +0,0 @@
-#pragma once
-
-
-namespace fast_io::operations
-{
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr ::fast_io::containers::span<char_type const> write_some_span(outstmtype &&outstm, ::fast_io::containers::span<char_type const> sp)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	return ::fast_io::containers::span<char_type const>(first, ::fast_io::details::write_some_impl(::fast_io::operations::output_stream_ref(outstm), first, last));
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr void write_all_span(outstmtype &&outstm, ::fast_io::containers::span<char_type const> sp)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	::fast_io::details::write_some_impl(::fast_io::operations::output_stream_ref(outstm), first, last);
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr ::fast_io::containers::span<::std::byte const> write_some_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::std::byte const> sp)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	return ::fast_io::containers::span<::std::byte const>(first, ::fast_io::details::write_some_bytes_impl(::fast_io::operations::output_stream_ref(outstm), first, last));
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr void write_all_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::std::byte const> sp)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	::fast_io::details::write_all_bytes_impl(::fast_io::operations::output_stream_ref(outstm), first, last);
-}
-
-template <typename outstmtype>
-inline constexpr io_scatter_status_t scatter_write_some_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::io_scatter_t const> sp)
-{
-	using io_scatter_may_alias_const_ptr
-#if __has_cpp_attribute(__gnu__::__may_alias__)
-		[[__gnu__::__may_alias__]]
-#endif
-		= io_scatter_t const *;
-	return ::fast_io::details::scatter_write_some_bytes_impl(::fast_io::operations::output_stream_ref(outstm),
-															 reinterpret_cast<io_scatter_may_alias_const_ptr>(sp.data()),
-															 sp.size());
-}
-
-template <typename outstmtype>
-inline constexpr void scatter_write_all_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::io_scatter_t const> sp)
-{
-	using io_scatter_may_alias_const_ptr
-#if __has_cpp_attribute(__gnu__::__may_alias__)
-		[[__gnu__::__may_alias__]]
-#endif
-		= io_scatter_t const *;
-	::fast_io::details::scatter_write_all_bytes_impl(::fast_io::operations::output_stream_ref(outstm),
-													 reinterpret_cast<io_scatter_may_alias_const_ptr>(sp.data()),
-													 sp.size());
-}
-
-template <typename outstmtype>
-inline constexpr io_scatter_status_t scatter_write_some_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::basic_io_scatter_t<typename decltype(::fast_io::operations::output_stream_ref(outstm))::output_char_type> const> sp)
-{
-	using io_scatter_may_alias_const_ptr
-#if __has_cpp_attribute(__gnu__::__may_alias__)
-		[[__gnu__::__may_alias__]]
-#endif
-		= basic_io_scatter_t<typename decltype(::fast_io::operations::output_stream_ref(outstm))::output_char_type> const *;
-	return ::fast_io::details::scatter_write_some_impl(::fast_io::operations::output_stream_ref(outstm),
-													   reinterpret_cast<io_scatter_may_alias_const_ptr>(sp.data()),
-													   sp.size());
-}
-
-template <typename outstmtype>
-inline constexpr void scatter_write_all_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::basic_io_scatter_t<typename decltype(::fast_io::operations::output_stream_ref(outstm))::output_char_type> const> sp)
-{
-	using io_scatter_may_alias_const_ptr
-#if __has_cpp_attribute(__gnu__::__may_alias__)
-		[[__gnu__::__may_alias__]]
-#endif
-		= basic_io_scatter_t<typename decltype(::fast_io::operations::output_stream_ref(outstm))::output_char_type> const *;
-	::fast_io::details::scatter_write_all_impl(::fast_io::operations::output_stream_ref(outstm),
-											   reinterpret_cast<io_scatter_may_alias_const_ptr>(sp.data()),
-											   sp.size());
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr ::fast_io::containers::span<char_type const> pwrite_some_span(outstmtype &&outstm, ::fast_io::containers::span<char_type const> sp, ::fast_io::intfpos_t off)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	return ::fast_io::containers::span<char_type const>(first, ::fast_io::details::pwrite_some_impl(::fast_io::operations::output_stream_ref(outstm), first, last, off));
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr void pwrite_all_span(outstmtype &&outstm, ::fast_io::containers::span<char_type const> sp, ::fast_io::intfpos_t off)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	::fast_io::details::pwrite_all_impl(::fast_io::operations::output_stream_ref(outstm), first, last, off);
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr ::fast_io::containers::span<::std::byte const> pwrite_some_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::std::byte const> sp, ::fast_io::intfpos_t off)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	return ::fast_io::containers::span<::std::byte const>(first, ::fast_io::details::pwrite_some_bytes_impl(::fast_io::operations::output_stream_ref(outstm), first, last, off));
-}
-
-template <typename outstmtype, ::std::integral char_type>
-#if __has_cpp_attribute(__gnu__::__always_inline__)
-[[__gnu__::__always_inline__]]
-#elif __has_cpp_attribute(msvc::forceinline)
-[[msvc::forceinline]]
-#endif
-inline constexpr void pwrite_all_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::std::byte const> sp, ::fast_io::intfpos_t off)
-{
-	auto first{sp.data()};
-	auto last{first + sp.size()};
-	::fast_io::details::pwrite_all_bytes_impl(::fast_io::operations::output_stream_ref(outstm), first, last, off);
-}
-
-template <typename outstmtype>
-inline constexpr io_scatter_status_t scatter_pwrite_some_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::io_scatter_t const> sp, ::fast_io::intfpos_t off)
-{
-
-	return ::fast_io::details::scatter_pwrite_some_bytes_impl(::fast_io::operations::output_stream_ref(outstm),
-															  sp.data(), sp.size(), off);
-}
-
-template <typename outstmtype>
-inline constexpr void scatter_pwrite_all_bytes_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::io_scatter_t const> sp, ::fast_io::intfpos_t off)
-{
-	::fast_io::details::scatter_pwrite_all_bytes_impl(::fast_io::operations::output_stream_ref(outstm),
-													  sp.data(), sp.size(), off);
-}
-
-template <typename outstmtype>
-inline constexpr io_scatter_status_t scatter_pwrite_some_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::basic_io_scatter_t<typename decltype(::fast_io::operations::output_stream_ref(outstm))::output_char_type> const> sp, ::fast_io::intfpos_t off)
-{
-	return ::fast_io::details::scatter_pwrite_some_impl(::fast_io::operations::output_stream_ref(outstm),
-														sp.data(), sp.size(), off);
-}
-
-template <typename outstmtype>
-inline constexpr void scatter_pwrite_all_span(outstmtype &&outstm, ::fast_io::containers::span<::fast_io::basic_io_scatter_t<typename decltype(::fast_io::operations::output_stream_ref(outstm))::output_char_type> const> sp, ::fast_io::intfpos_t off)
-{
-
-	::fast_io::details::scatter_pwrite_all_impl(::fast_io::operations::output_stream_ref(outstm), sp.data(), sp.size(), off);
-}
-
-} // namespace fast_io::operations
diff --git a/include/fast_io_dsal/impl/deque.h b/include/fast_io_dsal/impl/deque.h
index f376c3e4a..da04c2dbe 100644
--- a/include/fast_io_dsal/impl/deque.h
+++ b/include/fast_io_dsal/impl/deque.h
@@ -564,11 +564,16 @@ inline constexpr void deque_rebalance_or_grow_2x_after_blocks_impl(dequecontrolt
 }
 
 template <typename allocator, typename dequecontroltype>
-inline constexpr void deque_allocate_on_empty_common_impl(dequecontroltype &controller, ::std::size_t align, ::std::size_t bytes) noexcept
+inline constexpr void deque_allocate_on_empty_common_with_n_impl(dequecontroltype &controller, ::std::size_t align, ::std::size_t bytes,
+																 ::std::size_t initial_allocated_block_counts) noexcept
 {
+	constexpr ::std::size_t maxval{::std::numeric_limits<::std::size_t>::max()};
+	if (initial_allocated_block_counts == maxval) [[unlikely]]
+	{
+		::fast_io::fast_terminate();
+	}
+	::std::size_t initial_allocated_block_counts_with_sentinel{initial_allocated_block_counts + 1u};
 	using block_typed_allocator = ::fast_io::typed_generic_allocator_adapter<allocator, typename dequecontroltype::controlreplacetype>;
-	constexpr ::std::size_t initial_allocated_block_counts{3};
-	constexpr ::std::size_t initial_allocated_block_counts_with_sentinel{initial_allocated_block_counts + 1u};
 	auto [allocated_blocks_ptr, allocated_blocks_count] = block_typed_allocator::allocate_at_least(initial_allocated_block_counts_with_sentinel);
 	// we need a null terminator as sentinel like c style string does
 	--allocated_blocks_count;
@@ -596,6 +601,13 @@ inline constexpr void deque_allocate_on_empty_common_impl(dequecontroltype &cont
 	back_block.curr_ptr = halfposptr;
 }
 
+template <typename allocator, typename dequecontroltype>
+inline constexpr void deque_allocate_on_empty_common_impl(dequecontroltype &controller, ::std::size_t align, ::std::size_t bytes) noexcept
+{
+	constexpr ::std::size_t initial_allocated_block_counts{3};
+	::fast_io::containers::details::deque_allocate_on_empty_common_with_n_impl<allocator>(controller, align, bytes, initial_allocated_block_counts);
+}
+
 template <typename allocator, typename dequecontroltype>
 inline constexpr void deque_grow_back_common_impl(
 	dequecontroltype &controller,
@@ -1193,6 +1205,28 @@ deque_erase_common_trivial_impl(::fast_io::containers::details::deque_controller
 	return first;
 }
 
+#if 0
+template <typename allocator, typename dequecontroltype>
+inline constexpr void deque_reserve_back_spaces_impl(dequecontroltype &controller, ::std::size_t n, ::std::size_t align, ::std::size_t blockbytes) noexcept
+{
+	::std::size_t const nb{n/blockbytes};
+
+	if (controller.controller_block.controller_start_ptr == nullptr)
+	{
+		::fast_io::containers::details::deque_allocate_on_empty_common_with_n_impl<allocator>(
+			controller, align, blockbytes, nb);
+		return;
+	}
+	
+}
+
+template <typename allocator, ::std::size_t align, ::std::size_t sz, ::std::size_t block_size, typename dequecontroltype>
+inline constexpr void deque_reserve_back_spaces(dequecontroltype &controller, ::std::size_t n)
+{
+
+}
+#endif
+
 } // namespace details
 
 template <::std::forward_iterator ForwardIt>
@@ -1956,21 +1990,47 @@ class deque FAST_IO_TRIVIALLY_RELOCATABLE_IF_ELIGIBLE
 	inline constexpr insert_range_result insert_range_impl(size_type pos, R &&rg, size_type old_size) noexcept(::std::is_nothrow_constructible_v<value_type, ::std::ranges::range_value_t<R>>)
 	{
 #if 0
-		size_type const halfold_size{old_size >> 1u};
 		if constexpr(::std::ranges::sized_range<R>)
 		{
 			size_type const rgsize{::std::ranges::size(rg)};
+			size_type const half_size{old_size >> 1u};
+			if (pos < half_size)
+			{
+				
+			}
+			else
+			{
+			}
 		}
 		else
 #endif
 		{
-			this->append_range(rg);
-			auto bg{this->begin()};
-			iterator rotfirst = bg + pos;
-			iterator rotmid = bg + old_size;
-			iterator rotlast = this->end();
+			size_type const quarterold_size{old_size >> 2u};
+			size_type retpos;
+			iterator retit, rotfirst, rotmid, rotlast;
+			if (pos < quarterold_size)
+			{
+				this->prepend_range(rg);
+				size_type const new_size{this->size()};
+				size_type const inserted{new_size - old_size};
+				auto bg{this->begin()};
+				size_type newpos{pos + inserted};
+				rotfirst = bg;
+				rotmid = bg + inserted;
+				retpos = newpos;
+				retit = rotlast = bg + newpos;
+			}
+			else
+			{
+				this->append_range(rg);
+				auto bg{this->begin()};
+				rotfirst = retit = bg + pos;
+				rotmid = bg + old_size;
+				rotlast = this->end();
+				retpos = pos;
+			}
 			::fast_io::containers::rotate_for_fast_io_deque(rotfirst, rotmid, rotlast);
-			return {pos, rotfirst};
+			return {retpos, retit};
 		}
 	}
 
diff --git a/include/fast_io_hosted.h b/include/fast_io_hosted.h
index 446be4480..e003b8129 100644
--- a/include/fast_io_hosted.h
+++ b/include/fast_io_hosted.h
@@ -60,12 +60,12 @@ freestanding ones.
 #endif
 
 #if !defined(__AVR__)
+#include "fast_io_dsal/impl/common.h"
 #include "fast_io_dsal/impl/tuple.h"
 #include "fast_io_dsal/impl/string_view.h"
 #include "fast_io_dsal/impl/cstring_view.h"
 #include "fast_io_dsal/impl/string.h"
 #include "fast_io_dsal/impl/vector.h"
-
 #include "fast_io_hosted/platforms/native.h"
 #include "fast_io_hosted/file_loaders/impl.h"
 #include "fast_io_hosted/wrapper.h"
diff --git a/include/fast_io_hosted/process/process.h b/include/fast_io_hosted/process/process.h
index d39008d1e..f231846f4 100644
--- a/include/fast_io_hosted/process/process.h
+++ b/include/fast_io_hosted/process/process.h
@@ -1,3 +1,5 @@
 #pragma once
 #include "process/native.h"
+#if 0
 #include "ipc/native.h"
+#endif