diff --git a/include/bitcoin/system/boost.hpp b/include/bitcoin/system/boost.hpp
index 7b862baea3..88d123deb8 100644
--- a/include/bitcoin/system/boost.hpp
+++ b/include/bitcoin/system/boost.hpp
@@ -47,8 +47,7 @@
 // Include boost in cpp files only from here, so exception disable works.
 // Avoid use in header includes due to warning repetition (boost/format.hpp).
 #include <boost/algorithm/string.hpp>
-#include <boost/filesystem.hpp>
-#include <boost/format.hpp>
+////#include <boost/format.hpp>
 #include <boost/json.hpp>
 #include <boost/locale.hpp>
 #include <boost/multiprecision/cpp_int.hpp>
diff --git a/include/bitcoin/system/config/parser.hpp b/include/bitcoin/system/config/parser.hpp
index 18036e3421..97f486602b 100644
--- a/include/bitcoin/system/config/parser.hpp
+++ b/include/bitcoin/system/config/parser.hpp
@@ -19,8 +19,8 @@
 #ifndef LIBBITCOIN_SYSTEM_CONFIG_PARSER_HPP
 #define LIBBITCOIN_SYSTEM_CONFIG_PARSER_HPP
 
+#include <filesystem>
 #include <string>
-#include <boost/filesystem.hpp>
 #include <boost/program_options.hpp>
 #include <bitcoin/system/define.hpp>
 
@@ -49,7 +49,7 @@ class BC_API parser
         const std::string& message) noexcept;
     static bool get_option(variables_map& variables,
         const std::string& name) noexcept;
-    static boost::filesystem::path get_config_option(variables_map& variables,
+    static std::filesystem::path get_config_option(variables_map& variables,
         const std::string& name) noexcept;
 
     virtual ~parser() noexcept;
diff --git a/include/bitcoin/system/config/printer.hpp b/include/bitcoin/system/config/printer.hpp
index 7954649140..72ba090b55 100644
--- a/include/bitcoin/system/config/printer.hpp
+++ b/include/bitcoin/system/config/printer.hpp
@@ -67,8 +67,13 @@ class BC_API printer
         const std::string& application, const std::string& description="",
         const std::string& command="") noexcept;
 
-    /// Destructor.
-    virtual ~printer() noexcept;
+
+    /// Defaults.
+    printer(printer&&) = default;
+    printer(const printer&) = default;
+    printer& operator=(printer&&) = default;
+    printer& operator=(const printer&) = default;
+    virtual ~printer() = default;
 
     /// Convert a paragraph of text into a column.
     /// This formats to 80 char width as: [ 23 | ' ' | 55 | '\n' ].
diff --git a/include/bitcoin/system/unicode/utf8_everywhere/environment.hpp b/include/bitcoin/system/unicode/utf8_everywhere/environment.hpp
index 92a49da6da..cf54ddf37c 100644
--- a/include/bitcoin/system/unicode/utf8_everywhere/environment.hpp
+++ b/include/bitcoin/system/unicode/utf8_everywhere/environment.hpp
@@ -20,9 +20,9 @@
 #define LIBBITCOIN_SYSTEM_UNICODE_UTF8_EVERYWHERE_ENVIRONMENT_HPP
 
 #include <cstddef>
+#include <filesystem>
 #include <iostream>
 #include <string>
-#include <boost/filesystem.hpp>
 #include <bitcoin/system/define.hpp>
 
 namespace libbitcoin {
@@ -58,8 +58,8 @@ BC_API void set_binary_stdout() noexcept(false);
 // ----------------------------------------------------------------------------
 
 /// Get the default configuration file path with subdirectory.
-BC_API boost::filesystem::path default_config_path(
-    const boost::filesystem::path& subdirectory) noexcept;
+BC_API std::filesystem::path default_config_path(
+    const std::filesystem::path& subdirectory) noexcept;
 
 // BC_USE_LIBBITCOIN_MAIN dependencies.
 // ----------------------------------------------------------------------------
@@ -91,10 +91,10 @@ BC_API int call_utf8_main(int argc, wchar_t* argv[],
 #ifdef _MSC_VER
 // Not thread safe.
 BC_API std::wstring to_extended_path(
-    const boost::filesystem::path& path) noexcept;
+    const std::filesystem::path& path) noexcept;
 #else
 BC_API std::string to_extended_path(
-    const boost::filesystem::path& path) noexcept;
+    const std::filesystem::path& path) noexcept;
 #endif
 
 } // namespace system
diff --git a/include/bitcoin/system/unicode/utf8_everywhere/ifstream.hpp b/include/bitcoin/system/unicode/utf8_everywhere/ifstream.hpp
index 2c0157319e..7a65a3bdb3 100644
--- a/include/bitcoin/system/unicode/utf8_everywhere/ifstream.hpp
+++ b/include/bitcoin/system/unicode/utf8_everywhere/ifstream.hpp
@@ -19,8 +19,8 @@
 #ifndef LIBBITCOIN_SYSTEM_UNICODE_UTF8_EVERYWHERE_IFSTREAM_HPP
 #define LIBBITCOIN_SYSTEM_UNICODE_UTF8_EVERYWHERE_IFSTREAM_HPP
 
+#include <filesystem>
 #include <fstream>
-#include <boost/filesystem.hpp>
 #include <bitcoin/system/define.hpp>
 
 namespace libbitcoin {
@@ -33,7 +33,7 @@ class BC_API ifstream
 {
 public:
     /// This also opens the file.
-    ifstream(const boost::filesystem::path& path,
+    ifstream(const std::filesystem::path& path,
         std::ifstream::openmode mode=std::ifstream::in) noexcept(false);
 };
 
diff --git a/include/bitcoin/system/unicode/utf8_everywhere/ofstream.hpp b/include/bitcoin/system/unicode/utf8_everywhere/ofstream.hpp
index 4235530ba1..0295992318 100644
--- a/include/bitcoin/system/unicode/utf8_everywhere/ofstream.hpp
+++ b/include/bitcoin/system/unicode/utf8_everywhere/ofstream.hpp
@@ -19,8 +19,8 @@
 #ifndef LIBBITCOIN_SYSTEM_UNICODE_UTF8_EVERYWHERE_OFSTREAM_HPP
 #define LIBBITCOIN_SYSTEM_UNICODE_UTF8_EVERYWHERE_OFSTREAM_HPP
 
+#include <filesystem>
 #include <fstream>
-#include <boost/filesystem.hpp>
 #include <bitcoin/system/define.hpp>
 
 namespace libbitcoin {
@@ -33,7 +33,7 @@ class BC_API ofstream
 {
 public:
     /// This also opens the file.
-    ofstream(const boost::filesystem::path& path,
+    ofstream(const std::filesystem::path& path,
         std::ofstream::openmode mode=std::ofstream::out) noexcept(false);
 };
 
diff --git a/include/bitcoin/system/unicode/utf8_everywhere/utf8_everywhere.hpp b/include/bitcoin/system/unicode/utf8_everywhere/utf8_everywhere.hpp
index b4c1424e9b..8357e6848b 100644
--- a/include/bitcoin/system/unicode/utf8_everywhere/utf8_everywhere.hpp
+++ b/include/bitcoin/system/unicode/utf8_everywhere/utf8_everywhere.hpp
@@ -58,13 +58,15 @@
 // const auto utf16 = L"acción.кошка.日本国";
 // std::wcout << utf16;
 
-// Regarding Boost:
+// Regarding std lib (or boost) paths:
 //
 // When working with boost and utf8 narrow characters on Win32 the thread must
-// be configured for utf8. Also when working with boost::filesystem::path the
-// static path object must be imbued with the utf8 locale or paths will be
-// incorrectly translated. These changes are automatically configured by
+// be configured for utf8 (std::locale::global). This is configured by
 // BC_USE_LIBBITCOIN_MAIN.
+// When working with boost::filesystem::path the static path object must be
+// imbued with the utf8 locale or paths will be incorrectly translated.
+// When using std::filesystem::path this is handled by std::locale::global.
+// en.cppreference.com/w/cpp/filesystem/path/string
 
 // Regarding console applications:
 //
diff --git a/src/config/parser.cpp b/src/config/parser.cpp
index 55ea6a3969..385acd094e 100644
--- a/src/config/parser.cpp
+++ b/src/config/parser.cpp
@@ -18,6 +18,7 @@
  */
 #include <bitcoin/system/config/parser.hpp>
 
+#include <filesystem>
 #include <string>
 #include <sstream>
 #include <bitcoin/system/boost.hpp>
@@ -28,7 +29,7 @@ namespace libbitcoin {
 namespace system {
 namespace config {
 
-using namespace boost::filesystem;
+using namespace std::filesystem;
 using namespace boost::program_options;
 using namespace boost::system;
 
diff --git a/src/config/printer.cpp b/src/config/printer.cpp
index a4f2a40738..50a9f405a2 100644
--- a/src/config/printer.cpp
+++ b/src/config/printer.cpp
@@ -18,8 +18,10 @@
  */
 #include <bitcoin/system/config/printer.hpp>
 
+////#include <format>
 #include <string>
 #include <vector>
+#include <boost/format.hpp>
 #include <bitcoin/system/boost.hpp>
 #include <bitcoin/system/config/parameter.hpp>
 #include <bitcoin/system/data/data.hpp>
@@ -83,13 +85,10 @@ printer::printer(const po::options_description& settings,
 {
 }
 
-printer::~printer() noexcept
-{
-}
-
-/* Formatters */
+// Formatters
+// ----------------------------------------------------------------------------
 
-static void enqueue_fragment(std::string& fragment,
+static void enqueue_fragment(const std::string& fragment,
     std::vector<std::string>& column) noexcept
 {
     if (!fragment.empty())
@@ -386,7 +385,7 @@ std::string printer::format_usage_parameters() noexcept
     return trim_copy(usage.str());
 }
 
-/* Initialization */
+// Initialization
 
 static void enqueue_name(int count, std::string& name,
     argument_list& names) noexcept
@@ -477,7 +476,8 @@ void printer::initialize() noexcept
     generate_parameters();
 }
 
-/* Printers */
+// Printers
+// ----------------------------------------------------------------------------
 
 void printer::commandline(std::ostream& output) noexcept
 {
diff --git a/src/unicode/utf8_everywhere/environment.cpp b/src/unicode/utf8_everywhere/environment.cpp
index d49a6393a2..5c66fd7f6e 100644
--- a/src/unicode/utf8_everywhere/environment.cpp
+++ b/src/unicode/utf8_everywhere/environment.cpp
@@ -22,6 +22,7 @@
 #include <cstdlib>
 #include <cstring>
 #include <cwchar>
+#include <filesystem>
 #include <iostream>
 #include <locale>
 #include <mutex>
@@ -268,8 +269,8 @@ static std::string windows_config_directory() noexcept
 }
 #endif
 
-boost::filesystem::path default_config_path(
-    const boost::filesystem::path& subdirectory) noexcept
+std::filesystem::path default_config_path(
+    const std::filesystem::path& subdirectory) noexcept
 {
     static const std::string directory =
 #ifdef _MSC_VER
@@ -278,7 +279,7 @@ boost::filesystem::path default_config_path(
         SYSCONFDIR;
 #endif
 
-    return boost::filesystem::path{ directory } / subdirectory;
+    return std::filesystem::path{ directory } / subdirectory;
 }
 
 // BC_USE_LIBBITCOIN_MAIN
@@ -353,15 +354,10 @@ char** allocate_environment(wchar_t* environment[]) noexcept
 int call_utf8_main(int argc, wchar_t* argv[],
     int(*main)(int argc, char* argv[])) noexcept
 {
-    // C++17: use std::filesystem.
-    // When working with boost and utf8 narrow characters on Win32 the thread
-    // must be configured for utf8. When working with boost::filesystem::path
-    // the static path object must be imbued with the utf8 locale or paths will
-    // be incorrectly translated.
+    // TODO: verify std::filesystem::path is inbued as it was with boost.
     constexpr auto utf8_locale_name = "en_US.UTF8";
     boost::locale::generator locale;
     std::locale::global(locale(utf8_locale_name));
-    boost::filesystem::path::imbue(std::locale());
 
     auto backup = environ;
     auto environment = allocate_environment(_wenviron);
@@ -388,10 +384,9 @@ int call_utf8_main(int argc, wchar_t* argv[],
     return result;
 }
 
-// C++17: use std::filesystem.
 // docs.microsoft.com/windows/win32/api/fileapi/nf-fileapi-getfullpathnamew
 std::wstring to_fully_qualified_path(
-    const boost::filesystem::path& path) noexcept
+    const std::filesystem::path& path) noexcept
 {
     const auto replace_all = [](std::string text, char from, char to) noexcept
     {
@@ -431,7 +426,7 @@ std::wstring to_fully_qualified_path(
 #endif // _MSC_VER
 
 #ifdef _MSC_VER
-// C++17: use std::filesystem.
+// TODO: update comments for std::filesystem conversion.
 // Use to_extended_path with APIs that compile to wide with _MSC_VER defined
 // and to UTF8 with _MSC_VER undefined. This includes some boost APIs - such as
 // filesystem::remove, remove_all, and create_directories, as well as some
@@ -439,7 +434,7 @@ std::wstring to_fully_qualified_path(
 // Otherwise use in any Win32 (W) APIs with _MSC_VER defined, such as we do in 
 // interprocess_lock::open_file -> CreateFileW, since the boost wrapper only
 // calls CreateFileA. The length extension prefix requires Win32 (W) APIs.
-std::wstring to_extended_path(const boost::filesystem::path& path) noexcept
+std::wstring to_extended_path(const std::filesystem::path& path) noexcept
 {
     // The length extension prefix works only with a fully-qualified path.
     // However this includes "considered relative" paths (with ".." segments).
@@ -448,7 +443,7 @@ std::wstring to_extended_path(const boost::filesystem::path& path) noexcept
     return (full.length() > MAX_PATH) ? L"\\\\?\\" + full : full;
 }
 #else
-std::string to_extended_path(const boost::filesystem::path& path) noexcept
+std::string to_extended_path(const std::filesystem::path& path) noexcept
 {
     return path.string();
 }
diff --git a/src/unicode/utf8_everywhere/ifstream.cpp b/src/unicode/utf8_everywhere/ifstream.cpp
index 1c6e73c3a3..3d5bd363b5 100644
--- a/src/unicode/utf8_everywhere/ifstream.cpp
+++ b/src/unicode/utf8_everywhere/ifstream.cpp
@@ -18,16 +18,16 @@
  */
 #include <bitcoin/system/unicode/utf8_everywhere/ifstream.hpp>
 
+#include <filesystem>
 #include <fstream>
 #include <bitcoin/system/boost.hpp>
 #include <bitcoin/system/unicode/utf8_everywhere/environment.hpp>
 
 namespace libbitcoin {
 namespace system {
-    
-// C++17: use std::filesystem.
+ 
 // VC++ EXTENSION: "construct with wide-named file".
-ifstream::ifstream(const boost::filesystem::path& path,
+ifstream::ifstream(const std::filesystem::path& path,
     std::ifstream::openmode mode) noexcept(false)
   : std::ifstream(to_extended_path(path), mode)
 {
diff --git a/src/unicode/utf8_everywhere/ofstream.cpp b/src/unicode/utf8_everywhere/ofstream.cpp
index a7c9e86fdc..e740bb38c0 100644
--- a/src/unicode/utf8_everywhere/ofstream.cpp
+++ b/src/unicode/utf8_everywhere/ofstream.cpp
@@ -18,6 +18,7 @@
  */
 #include <bitcoin/system/unicode/utf8_everywhere/ofstream.hpp>
 
+#include <filesystem>
 #include <fstream>
 #include <bitcoin/system/boost.hpp>
 #include <bitcoin/system/unicode/utf8_everywhere/environment.hpp>
@@ -25,9 +26,8 @@
 namespace libbitcoin {
 namespace system {
     
-// C++17: use std::filesystem.
 // VC++ EXTENSION: "construct with wide-named file".
-ofstream::ofstream(const boost::filesystem::path& path,
+ofstream::ofstream(const std::filesystem::path& path,
     std::ofstream::openmode mode) noexcept(false)
   : std::ofstream(to_extended_path(path), mode)
 {
diff --git a/test/config/parameter.cpp b/test/config/parameter.cpp
index cc49709c07..fbbdde14e5 100644
--- a/test/config/parameter.cpp
+++ b/test/config/parameter.cpp
@@ -17,6 +17,7 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 #include "../test.hpp"
+#include <filesystem>
 #include <iostream>
 #include <utility>
 #include <vector>
@@ -42,7 +43,7 @@ enum opt
 
 static void load_test_options(po::options_description& options)
 {
-    using namespace boost::filesystem;
+    using namespace std::filesystem;
     using namespace boost::program_options;
     options.add_options()
         ("short_long,s", "Long and short name.")
diff --git a/test/config/printer.cpp b/test/config/printer.cpp
index 0e14dffe51..1f40373ea3 100644
--- a/test/config/printer.cpp
+++ b/test/config/printer.cpp
@@ -294,7 +294,7 @@ BOOST_AUTO_TEST_CASE(printer__format_usage_parameters__unsorted_two_options_one_
 
 BOOST_AUTO_TEST_CASE(printer__format_usage_parameters__unsorted_multiple_parameters__sorted_parameters)
 {
-    using namespace boost::filesystem;
+    using namespace std::filesystem;
     using namespace boost::program_options;
     CONFIG_PRINTER_SETUP_ARGUMENTS(options.add_options()
         ("short_long,s", "Long and short name.")
diff --git a/test/test.cpp b/test/test.cpp
index 4a3b3c3e56..89db09fe20 100644
--- a/test/test.cpp
+++ b/test/test.cpp
@@ -19,7 +19,7 @@
 #include "test.hpp"
 
 #include <iostream>
-#include <boost/filesystem.hpp>
+#include <filesystem>
 #include <bitcoin/system.hpp>
 
 namespace std {
@@ -41,21 +41,18 @@ namespace test {
 
 const std::string directory = "tests";
 
-// C++17: use std::filesystem.
-bool clear(const boost::filesystem::path& file_directory) noexcept
+bool clear(const std::filesystem::path& file_directory) noexcept
 {
-    // C++17: use std::filesystem.
     // remove_all returns count removed, and error code if fails.
     // create_directories returns true if path exists or created.
     // used for setup, with no expectations of file/directory existence.
     const auto path = to_extended_path(file_directory);
-    boost::system::error_code ec;
-    boost::filesystem::remove_all(path, ec);
-    return !ec && boost::filesystem::create_directories(path, ec);
+    code ec;
+    std::filesystem::remove_all(path, ec);
+    return !ec && std::filesystem::create_directories(path, ec);
 }
 
-// C++17: use std::filesystem.
-bool create(const boost::filesystem::path& file_path) noexcept
+bool create(const std::filesystem::path& file_path) noexcept
 {
     // Creates and returns true if file already existed (and no error).
     BC_PUSH_WARNING(NO_THROW_IN_NOEXCEPT)
@@ -64,8 +61,7 @@ bool create(const boost::filesystem::path& file_path) noexcept
     BC_POP_WARNING()
 }
 
-// C++17: use std::filesystem.
-bool exists(const boost::filesystem::path& file_path) noexcept
+bool exists(const std::filesystem::path& file_path) noexcept
 {
     // Returns true only if file existed.
     BC_PUSH_WARNING(NO_THROW_IN_NOEXCEPT)
@@ -74,13 +70,11 @@ bool exists(const boost::filesystem::path& file_path) noexcept
     BC_POP_WARNING()
 }
 
-// C++17: use std::filesystem.
-bool remove(const boost::filesystem::path& file_path) noexcept
+bool remove(const std::filesystem::path& file_path) noexcept
 {
-    // C++17: use std::filesystem.
     // Deletes and returns false if file did not exist (or error).
-    boost::system::error_code ec;
-    return boost::filesystem::remove(to_extended_path(file_path), ec);
+    code ec;
+    return std::filesystem::remove(to_extended_path(file_path), ec);
 }
 
 } // namespace test
\ No newline at end of file
diff --git a/test/test.hpp b/test/test.hpp
index a6c2c5496f..bee5b7eca4 100644
--- a/test/test.hpp
+++ b/test/test.hpp
@@ -24,6 +24,7 @@
 #include <array>
 #include <iostream>
 #include <vector>
+#include <filesystem>
 #include <bitcoin/system.hpp>
 
 #define TEST_NAME \
@@ -89,10 +90,10 @@ namespace test {
 // Total path length cannot exceed MAX_PATH in _MSC_VER builds.
 extern const std::string directory;
 
-bool clear(const boost::filesystem::path& directory) noexcept;
-bool create(const boost::filesystem::path& file_path) noexcept;
-bool exists(const boost::filesystem::path& file_path) noexcept;
-bool remove(const boost::filesystem::path& file_path) noexcept;
+bool clear(const std::filesystem::path& directory) noexcept;
+bool create(const std::filesystem::path& file_path) noexcept;
+bool exists(const std::filesystem::path& file_path) noexcept;
+bool remove(const std::filesystem::path& file_path) noexcept;
 
 } // namespace test