diff --git a/sprout/assert.hpp b/sprout/assert.hpp
index 5e5a3a3f..52004431 100644
--- a/sprout/assert.hpp
+++ b/sprout/assert.hpp
@@ -79,6 +79,16 @@ namespace sprout {
 		}
 	};
 
+	//
+	// assertion_failed_msg_default
+	//
+	inline SPROUT_NON_CONSTEXPR bool
+	assertion_failed_default(sprout::assertion_info_msg const& info) {
+		return (std::cerr << "***** Internal Program Error - assertion (" << info.expr() << ") failed: " << info.file() << "(" << info.line() << ")" << ": " << msg << std::endl),
+			std::abort(), false
+			;
+	}
+
 	//
 	// assertion_failed_msg
 	//	* user defined
@@ -172,6 +182,16 @@ namespace sprout {
 		}
 	};
 
+	//
+	// assertion_failed_default
+	//
+	inline SPROUT_NON_CONSTEXPR bool
+	assertion_failed_default(sprout::assertion_info const& info) {
+		return (std::cerr << "***** Internal Program Error - assertion (" << info.expr() << ") failed: " << info.file() << "(" << info.line() << ")" << std::endl),
+			std::abort(), false
+			;
+	}
+
 	//
 	// assertion_failed
 	//	* user defined
diff --git a/testspr/print.hpp b/testspr/print.hpp
index 5485219d..8530e622 100644
--- a/testspr/print.hpp
+++ b/testspr/print.hpp
@@ -12,8 +12,10 @@
 #include <iterator>
 #include <bitset>
 #include <utility>
-#include <iostream>
+#include <string>
+#include <sstream>
 #include <iomanip>
+#include <iostream>
 #include <sprout/config.hpp>
 #include <sprout/preprocessor/config.hpp>
 #include <sprout/preprocessor/stringize.hpp>
@@ -131,6 +133,25 @@ namespace testspr {
 	print_hl() {
 		testspr::print_ln("--------------------------------------------------------------------------------");
 	}
+	template<typename T>
+	inline SPROUT_NON_CONSTEXPR void
+	print_hl(char c) {
+		for (std::string::size_type i = 0, last = 80; i != last; ++i) {
+			std::cout << c;
+		}
+		std::cout << std::endl;
+	}
+	template<typename T>
+	inline SPROUT_NON_CONSTEXPR void
+	print_hl(T const& t) {
+		std::ostringstream oss;
+		oss << t;
+		std::string s(oss.str());
+		for (std::string::size_type i = 0, last = 80 / s.size(); i != last; ++i) {
+			std::cout << s;
+		}
+		std::cout << std::endl;
+	}
 
 	//
 	// manip_holder
diff --git a/testspr/singleton.hpp b/testspr/singleton.hpp
new file mode 100644
index 00000000..083a445a
--- /dev/null
+++ b/testspr/singleton.hpp
@@ -0,0 +1,90 @@
+/*=============================================================================
+  Copyright (c) 2011-2017 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  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 TESTSPR_SINGLETON_HPP
+#define TESTSPR_SINGLETON_HPP
+
+#include <sprout/config.hpp>
+#include <sprout/utility/noncopyable.hpp>
+#include <sprout/assert.hpp>
+
+namespace testspr {
+	//
+	// singleton_module
+	//
+	class singleton_module
+		: public sprout::noncopyable
+	{
+	private:
+		static inline SPROUT_NON_CONSTEXPR bool& get_lock() {
+			static bool lock = false;
+			return lock;
+		}
+	public:
+		static inline SPROUT_NON_CONSTEXPR void lock() {
+			get_lock() = true;
+		}
+		static inline SPROUT_NON_CONSTEXPR void unlock() {
+			get_lock() = false;
+		}
+		static inline SPROUT_NON_CONSTEXPR bool is_locked() {
+			return get_lock();
+		}
+	};
+
+	namespace detail {
+		template<typename T>
+		class singleton_wrapper
+			: public T
+		{
+		public:
+			static bool m_is_destroyed;
+		public:
+			~singleton_wrapper() {
+				m_is_destroyed = true;
+			}
+		};
+		template<typename T>
+		bool testspr::detail::singleton_wrapper<T>::m_is_destroyed = false;
+	}	// namespace detail
+
+	//
+	// singleton
+	//
+	template<typename T>
+	class singleton
+		: public testspr::singleton_module
+	{
+	public:
+		typedef T instance_type;
+	private:
+		static instance_type& instance;
+	private:
+		static inline SPROUT_NON_CONSTEXPR void use(const instance_type&) {}
+		static inline SPROUT_NON_CONSTEXPR instance_type& get_instance() {
+			static detail::singleton_wrapper<instance_type> t;
+			SPROUT_ASSERT(!testspr::detail::singleton_wrapper<instance_type>::m_is_destroyed);
+			use(instance);
+			return static_cast<instance_type&>(t);
+		}
+	public:
+		static inline SPROUT_NON_CONSTEXPR instance_type& get_mutable_instance() {
+			SPROUT_ASSERT(!is_locked());
+			return get_instance();
+		}
+		static inline SPROUT_NON_CONSTEXPR instance_type const& get_const_instance() {
+			return get_instance();
+		}
+		static inline SPROUT_NON_CONSTEXPR bool is_destroyed() {
+			return testspr::detail::singleton_wrapper<instance_type>::m_is_destroyed;
+		}
+	};
+	template<typename T>
+	T& singleton<T>::instance = testspr::singleton<T>::get_instance();
+}	// namespace testspr
+
+#endif	// #ifndef TESTSPR_SINGLETON_HPP
diff --git a/testspr/tools.hpp b/testspr/tools.hpp
index 45ed8c81..a59a1140 100644
--- a/testspr/tools.hpp
+++ b/testspr/tools.hpp
@@ -15,6 +15,8 @@
 #include <testspr/range.hpp>
 #include <testspr/utility.hpp>
 #include <testspr/typeinfo.hpp>
+#include <testspr/singleton.hpp>
 #include <testspr/print.hpp>
+#include <testspr/trace.hpp>
 
 #endif	// #ifndef TESTSPR_TOOLS_HPP
diff --git a/testspr/trace.hpp b/testspr/trace.hpp
new file mode 100644
index 00000000..dba74942
--- /dev/null
+++ b/testspr/trace.hpp
@@ -0,0 +1,551 @@
+/*=============================================================================
+  Copyright (c) 2011-2017 Bolero MURAKAMI
+  https://github.com/bolero-MURAKAMI/Sprout
+
+  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 TESTSPR_TRACE_HPP
+#define TESTSPR_TRACE_HPP
+
+#include <cstdlib>
+#include <algorithm>
+#include <functional>
+#include <vector>
+#include <utility>
+#include <string>
+#include <typeinfo>
+#include <iostream>
+#include <sprout/config.hpp>
+#include <sprout/utility/forward.hpp>
+#include <sprout/preprocessor/stringize.hpp>
+#include <sprout/current_function.hpp>
+#include <sprout/assert.hpp>
+//#include <testspr/singleton.hpp>
+#include <testspr/typeinfo.hpp>
+#include <testspr/print.hpp>
+
+namespace testspr {
+	//
+	// trace_info
+	//
+	class trace_info {
+	private:
+		std::string file_;
+		long line_;
+		std::string tag_;
+		std::string what_;
+	public:
+		SPROUT_NON_CONSTEXPR trace_info(std::string const& file, long line)
+			: file_(file), line_(line), tag_("(unknown)"), what_("(unknown)")
+		{}
+		SPROUT_NON_CONSTEXPR trace_info(std::string const& file, long line, std::string const& tag)
+			: file_(file), line_(line), tag_(tag), what_("(unknown)")
+		SPROUT_NON_CONSTEXPR {}
+		trace_info(std::string const& file, long line, std::string const& tag, std::string const& what)
+			: file_(file), line_(line), tag_(tag), what_(what)
+		{}
+		SPROUT_NON_CONSTEXPR std::string const& file() const {
+			return file_;
+		}
+		SPROUT_NON_CONSTEXPR long line() const {
+			return line_;
+		}
+		SPROUT_NON_CONSTEXPR std::string const& tag() const {
+			return tag_;
+		}
+		SPROUT_NON_CONSTEXPR std::string const& what() const {
+			return what_;
+		}
+	};
+
+	//
+	// trace_record
+	//
+	class trace_record
+		: public testspr::singleton<testspr::trace_record>
+	{
+	private:
+		typedef testspr::singleton<testspr::trace_record> self_type;
+	public:
+		typedef std::vector<std::pair<std::string, testspr::trace_info> > container_type;
+		typedef container_type::size_type size_type;
+		typedef container_type::value_type value_type;
+		typedef container_type::reference reference;
+		typedef container_type::const_reference const_reference;
+		typedef container_type::iterator iterator;
+		typedef container_type::const_iterator const_iterator;
+	public:
+		static inline SPROUT_NON_CONSTEXPR trace_record& instance() {
+			return get_mutable_instance();
+		}
+	private:
+		container_type info_;
+	public:
+		SPROUT_NON_CONSTEXPR void push(std::string const& command, testspr::trace_info const& info) {
+			info_.emplace_back(command, info);
+		}
+		SPROUT_NON_CONSTEXPR void pop() {
+			info_.pop_back();
+		}
+		SPROUT_NON_CONSTEXPR reference top() {
+			return info_.back();
+		}
+		SPROUT_NON_CONSTEXPR const_reference top() const {
+			return info_.back();
+		}
+		SPROUT_NON_CONSTEXPR size_type size() const {
+			return info_.size();
+		}
+		SPROUT_NON_CONSTEXPR iterator begin() {
+			return info_.begin();
+		}
+		SPROUT_NON_CONSTEXPR iterator end() {
+			return info_.end();
+		}
+		SPROUT_NON_CONSTEXPR const_iterator begin() const {
+			return info_.begin();
+		}
+		SPROUT_NON_CONSTEXPR const_iterator end() const {
+			return info_.end();
+		}
+		SPROUT_NON_CONSTEXPR const_iterator cbegin() const {
+			return info_.cbegin();
+		}
+		SPROUT_NON_CONSTEXPR const_iterator cend() const {
+			return info_.cend();
+		}
+		SPROUT_NON_CONSTEXPR void clear() {
+			info_.clear();
+		}
+		template<typename OutputIterator>
+		SPROUT_NON_CONSTEXPR void copy(OutputIterator out) const {
+			std::copy(begin(), end(), out);
+		}
+		SPROUT_NON_CONSTEXPR void print() const {
+			testspr::print_ln("trace-record current: size:", size(), ":");
+			for (const_iterator it = cbegin(), last = cend(); it != last; ++it) {
+				testspr::print_ln("  ", it->first, " - ", it->second.file(), ":", it->second.line(), ": ", it->second.tag(), ": ", it->second.what());
+			}
+		}
+	};
+
+	//
+	// trace_stack
+	//
+	class trace_stack
+		: public testspr::singleton<testspr::trace_stack>
+	{
+	private:
+		typedef testspr::singleton<testspr::trace_stack> self_type;
+	public:
+		typedef std::vector<testspr::trace_info> container_type;
+		typedef container_type::size_type size_type;
+		typedef container_type::value_type value_type;
+		typedef container_type::reference reference;
+		typedef container_type::const_reference const_reference;
+		typedef container_type::iterator iterator;
+		typedef container_type::const_iterator const_iterator;
+		typedef std::function<bool (testspr::trace_stack const&)> function_type;
+	private:
+		class comparable_function {
+		private:
+			function_type func_;
+		public:
+			SPROUT_NON_CONSTEXPR comparable_function(function_type const& f)
+				: func_(f)
+			{}
+			SPROUT_NON_CONSTEXPR bool operator()(trace_stack const& t) {
+				return func_(t);
+			}
+			SPROUT_NON_CONSTEXPR bool operator==(function_type const& rhs) {
+				return func_.target_type() == rhs.target_type();
+			}
+			SPROUT_NON_CONSTEXPR bool operator!=(function_type const& rhs) {
+				return func_.target_type() != rhs.target_type();
+			}
+		};
+	private:
+		typedef std::vector<comparable_function> function_container_type;
+	private:
+		class print_on_push {
+		public:
+			SPROUT_NON_CONSTEXPR bool operator()(testspr::trace_stack const& stack) const {
+				testspr::trace_info const& info = stack.top();
+				testspr::print_ln("trace-stack push: ", info.file(), ":", info.line(), ": ", info.tag(), ": ", info.what());
+				return false;
+			}
+		};
+		class print_on_pop {
+		public:
+			SPROUT_NON_CONSTEXPR bool operator()(testspr::trace_stack const& stack) const {
+				testspr::trace_info const& info = stack.top();
+				testspr::print_ln("trace-stack pop: ", info.file(), ":", info.line(), ": ", info.tag(), ": ", info.what());
+				return false;
+			}
+		};
+		class record_on_push {
+		public:
+			SPROUT_NON_CONSTEXPR bool operator()(testspr::trace_stack const& stack) const {
+				testspr::trace_record::instance().push("push", stack.top());
+				return false;
+			}
+		};
+		class record_on_pop {
+		public:
+			SPROUT_NON_CONSTEXPR bool operator()(testspr::trace_stack const& stack) const {
+				testspr::trace_record::instance().push("pop", stack.top());
+				return false;
+			}
+		};
+		class print_on_notify {
+		public:
+			SPROUT_NON_CONSTEXPR bool operator()(testspr::trace_stack const& stack) const {
+				testspr::trace_info const& info = stack.top();
+				testspr::print_ln("trace-stack notify: ", info.file(), ":", info.line(), ": ", info.tag(), ": ", info.what());
+				if (info.tag() == "assertion-failed") {
+					testspr::trace_stack::instance().print();
+					testspr::trace_record::instance().print();
+				}
+				return false;
+			}
+		};
+		class record_on_notify {
+		public:
+			SPROUT_NON_CONSTEXPR bool operator()(testspr::trace_stack const& stack) const {
+				testspr::trace_record::instance().push("notify", stack.top());
+				return false;
+			}
+		};
+	public:
+		static inline SPROUT_NON_CONSTEXPR trace_stack& instance() {
+			return get_mutable_instance();
+		}
+	private:
+		container_type info_;
+		function_container_type callback_on_push_;
+		function_container_type callback_on_pop_;
+		function_container_type callback_on_notify_;
+	private:
+		SPROUT_NON_CONSTEXPR bool callback_on_push() {
+			for (function_container_type::iterator it = callback_on_push_.begin(), last = callback_on_push_.end(); it != last; ++it) {
+				if ((*it)(*this)) {
+					return true;
+				}
+			}
+			return false;
+		}
+		SPROUT_NON_CONSTEXPR bool callback_on_pop() {
+			for (function_container_type::reverse_iterator it = callback_on_pop_.rbegin(), last = callback_on_pop_.rend(); it != last; ++it) {
+				if ((*it)(*this)) {
+					return true;
+				}
+			}
+			return false;
+		}
+		SPROUT_NON_CONSTEXPR bool callback_on_notify() {
+			for (function_container_type::iterator it = callback_on_notify_.begin(), last = callback_on_notify_.end(); it != last; ++it) {
+				if ((*it)(*this)) {
+					return true;
+				}
+			}
+			return false;
+		}
+	public:
+		SPROUT_NON_CONSTEXPR void push(std::string const& file, long line) {
+			info_.emplace_back(file, line);
+			callback_on_push();
+		}
+		SPROUT_NON_CONSTEXPR void push(std::string const& file, long line, std::string const& tag) {
+			info_.emplace_back(file, line, tag);
+			callback_on_push();
+		}
+		SPROUT_NON_CONSTEXPR void push(std::string const& file, long line, std::string const& tag, std::string const& what) {
+			info_.emplace_back(file, line, tag, what);
+			callback_on_push();
+		}
+		SPROUT_NON_CONSTEXPR void pop() {
+			callback_on_pop();
+			info_.pop_back();
+		}
+		SPROUT_NON_CONSTEXPR reference top() {
+			return info_.back();
+		}
+		SPROUT_NON_CONSTEXPR const_reference top() const {
+			return info_.back();
+		}
+		SPROUT_NON_CONSTEXPR size_type size() const {
+			return info_.size();
+		}
+		SPROUT_NON_CONSTEXPR iterator begin() {
+			return info_.begin();
+		}
+		SPROUT_NON_CONSTEXPR iterator end() {
+			return info_.end();
+		}
+		SPROUT_NON_CONSTEXPR const_iterator begin() const {
+			return info_.begin();
+		}
+		SPROUT_NON_CONSTEXPR const_iterator end() const {
+			return info_.end();
+		}
+		SPROUT_NON_CONSTEXPR const_iterator cbegin() const {
+			return info_.cbegin();
+		}
+		SPROUT_NON_CONSTEXPR const_iterator cend() const {
+			return info_.cend();
+		}
+		template<typename OutputIterator>
+		SPROUT_NON_CONSTEXPR void copy(OutputIterator out) const {
+			std::copy(begin(), end(), out);
+		}
+		SPROUT_NON_CONSTEXPR void print() const {
+			testspr::print_ln("trace-stack current: size:", size(), ":");
+			for (const_iterator it = cbegin(), last = cend(); it != last; ++it) {
+				testspr::print_ln("  ", it->file(), ":", it->line(), ": ", it->tag(), ": ", it->what());
+			}
+		}
+
+		SPROUT_NON_CONSTEXPR void notify_assertion_failed(std::string const& expr, std::string const& file, long line) {
+			info_.emplace_back(file, line, "assertion-failed", expr);
+			callback_on_notify();
+			info_.pop_back();
+		}
+		template<typename E>
+		SPROUT_NON_CONSTEXPR void notify_throw_exception(E const& exception, std::string const& file, long line) {
+			info_.emplace_back(file, line, "throw-exception", testspr::typename_of(exception));
+			callback_on_notify();
+			info_.pop_back();
+		}
+		template<typename E>
+		SPROUT_NON_CONSTEXPR void notify_caught_exception(E const& exception, std::string const& file, long line) {
+			info_.emplace_back(file, line, "caught-exception", testspr::typename_of(exception));
+			callback_on_notify();
+			info_.pop_back();
+		}
+		SPROUT_NON_CONSTEXPR void notify_mark(std::string const& name, std::string const& file, long line) {
+			info_.emplace_back(file, line, "mark", name);
+			callback_on_notify();
+			info_.pop_back();
+		}
+
+		SPROUT_NON_CONSTEXPR void push_callback_on_push(function_type const& callback) {
+			callback_on_push_.push_back(callback);
+		}
+		SPROUT_NON_CONSTEXPR void pop_callback_on_push(function_type const& callback) {
+			function_container_type::reverse_iterator rfound
+				= std::find(callback_on_push_.rbegin(), callback_on_push_.rend(), callback);
+			if (rfound != callback_on_push_.rend()) {
+				callback_on_push_.erase(rfound.base() - 1);
+			}
+		}
+		SPROUT_NON_CONSTEXPR void push_callback_on_pop(function_type const& callback) {
+			callback_on_pop_.push_back(callback);
+		}
+		SPROUT_NON_CONSTEXPR void pop_callback_on_pop(function_type const& callback) {
+			function_container_type::reverse_iterator rfound
+				= std::find(callback_on_pop_.rbegin(), callback_on_pop_.rend(), callback);
+			if (rfound != callback_on_pop_.rend()) {
+				callback_on_pop_.erase(rfound.base() - 1);
+			}
+		}
+		SPROUT_NON_CONSTEXPR void push_callback_on_notify(function_type const& callback) {
+			callback_on_notify_.push_back(callback);
+		}
+		SPROUT_NON_CONSTEXPR void pop_callback_on_notify(function_type const& callback) {
+			function_container_type::reverse_iterator rfound
+				= std::find(callback_on_notify_.rbegin(), callback_on_notify_.rend(), callback);
+			if (rfound != callback_on_notify_.rend()) {
+				callback_on_notify_.erase(rfound.base() - 1);
+			}
+		}
+
+		SPROUT_NON_CONSTEXPR void enable_print_on_entry() {
+			{
+				function_type callback = print_on_push();
+				function_container_type::iterator found
+					= std::find(callback_on_push_.begin(), callback_on_push_.end(), callback);
+				if (found == callback_on_push_.end()) {
+					push_callback_on_push(callback);
+				}
+			}
+			{
+				function_type callback = print_on_pop();
+				function_container_type::iterator found
+					= std::find(callback_on_pop_.begin(), callback_on_pop_.end(), callback);
+				if (found == callback_on_pop_.end()) {
+					push_callback_on_pop(callback);
+				}
+			}
+			{
+				function_type callback = print_on_notify();
+				function_container_type::iterator found
+					= std::find(callback_on_notify_.begin(), callback_on_notify_.end(), callback);
+				if (found == callback_on_notify_.end()) {
+					push_callback_on_notify(callback);
+				}
+			}
+		}
+		SPROUT_NON_CONSTEXPR void disable_print_on_entry() {
+			{
+				function_type callback = print_on_push();
+				pop_callback_on_push(callback);
+			}
+			{
+				function_type callback = print_on_pop();
+				pop_callback_on_pop(callback);
+			}
+			{
+				function_type callback = print_on_notify();
+				pop_callback_on_notify(callback);
+			}
+		}
+
+		SPROUT_NON_CONSTEXPR void enable_record_on_entry() {
+			{
+				function_type callback = record_on_push();
+				function_container_type::iterator found
+					= std::find(callback_on_push_.begin(), callback_on_push_.end(), callback);
+				if (found == callback_on_push_.end()) {
+					push_callback_on_push(callback);
+				}
+			}
+			{
+				function_type callback = record_on_pop();
+				function_container_type::iterator found
+					= std::find(callback_on_pop_.begin(), callback_on_pop_.end(), callback);
+				if (found == callback_on_pop_.end()) {
+					push_callback_on_pop(callback);
+				}
+			}
+			{
+				function_type callback = record_on_notify();
+				function_container_type::iterator found
+					= std::find(callback_on_notify_.begin(), callback_on_notify_.end(), callback);
+				if (found == callback_on_notify_.end()) {
+					push_callback_on_notify(callback);
+				}
+			}
+		}
+		SPROUT_NON_CONSTEXPR void disable_record_on_entry() {
+			{
+				function_type callback = record_on_push();
+				pop_callback_on_push(callback);
+			}
+			{
+				function_type callback = record_on_pop();
+				pop_callback_on_pop(callback);
+			}
+			{
+				function_type callback = record_on_notify();
+				pop_callback_on_notify(callback);
+			}
+		}
+	};
+
+	//
+	// function_tracer
+	//
+	class function_tracer {
+	public:
+		SPROUT_NON_CONSTEXPR function_tracer(std::string const& file, long line) {
+			testspr::trace_stack::instance().push(file, line, "function");
+		}
+		SPROUT_NON_CONSTEXPR function_tracer(std::string const& file, long line, std::string const& function) {
+			testspr::trace_stack::instance().push(file, line, "function", function);
+		}
+		~function_tracer() SPROUT_NOEXCEPT {
+			testspr::trace_stack::instance().pop();
+		}
+	};
+	//
+	// TESTSPR_TRACE_FUNCTION
+	//
+#	define TESTSPR_TRACE_FUNCTION() \
+		testspr::function_tracer SPROUT_PP_CAT(testspr_function_tracer_, __LINE__)(__FILE__, __LINE__, SPROUT_CURRENT_FUNCTION)
+	//
+	// TESTSPR_TRACE_FUNCTION_EXPR
+	//
+#	define TESTSPR_TRACE_FUNCTION_EXPR() \
+		((void)testspr::function_tracer(__FILE__, __LINE__, SPROUT_CURRENT_FUNCTION))
+
+	//
+	// block_tracer
+	//
+	class block_tracer {
+	public:
+		SPROUT_NON_CONSTEXPR block_tracer(std::string const& file, long line) {
+			testspr::trace_stack::instance().push(file, line, "block");
+		}
+		SPROUT_NON_CONSTEXPR block_tracer(std::string const& file, long line, std::string const& name) {
+			testspr::trace_stack::instance().push(file, line, "block", name);
+		}
+		~block_tracer() SPROUT_NOEXCEPT {
+			testspr::trace_stack::instance().pop();
+		}
+	};
+	//
+	// TESTSPR_TRACE_BLOCK
+	//
+#	define TESTSPR_TRACE_BLOCK(name) \
+		testspr::block_tracer SPROUT_PP_CAT(testspr_block_tracer_, __LINE__)(__FILE__, __LINE__, name)
+	//
+	// TESTSPR_TRACE_BLOCK_EXPR
+	//
+#	define TESTSPR_TRACE_BLOCK_EXPR(name) \
+		((void)testspr::block_tracer(__FILE__, __LINE__, name))
+
+	namespace detail {
+		inline SPROUT_NON_CONSTEXPR bool
+		trace_assertion_failed(char const* formatted, char const* expr, char const* file, long line) {
+			testspr::trace_stack::instance().notify_assertion_failed(expr, file, line);
+			return (std::cerr << formatted << std::endl), std::abort(), false;
+		}
+		inline SPROUT_NON_CONSTEXPR bool
+		trace_assertion_check(bool cond, char const* formatted, char const* expr, char const* file, long line) {
+			return cond ? true
+				: testspr::detail::trace_assertion_failed(formatted, expr, file, line)
+				;
+		}
+	}	// namespace detail
+	//
+	// TESTSPR_TRACE_ASSERT
+	//
+#	define TESTSPR_TRACE_ASSERT(expr) \
+		((void)testspr::detail::trace_assertion_check((expr), SPROUT_ASSERTION_FAILED_FORMAT(expr, __FILE__, __LINE__), SPROUT_PP_STRINGIZE((expr)), __FILE__, __LINE__))
+
+	namespace detail {
+		template<typename E>
+		inline SPROUT_NON_CONSTEXPR void
+		trace_throw(E&& exception, char const* file, long line) {
+			testspr::trace_stack::instance().notify_throw_exception(exception, file, line);
+			throw sprout::forward<E>(exception);
+		}
+	}	// namespace detail
+	//
+	// TESTSPR_TRACE_THROW
+	//
+#	define TESTSPR_TRACE_THROW(e) \
+		((void)testspr::detail::trace_throw(e, __FILE__, __LINE__))
+
+	namespace detail {
+		template<typename E>
+		inline SPROUT_NON_CONSTEXPR void
+		trace_caught(E&& exception, char const* file, long line) {
+			testspr::trace_stack::instance().notify_caught_exception(exception, file, line);
+		}
+	}	// namespace detail
+	//
+	// TESTSPR_TRACE_CAUGHT
+	//
+#	define TESTSPR_TRACE_CAUGHT(e) \
+		((void)testspr::detail::trace_caught(e, __FILE__, __LINE__))
+
+	//
+	// TESTSPR_TRACE_MARK
+	//
+#	define TESTSPR_TRACE_MARK(name) \
+		((void)testspr::trace_stack::instance().notify_mark(name, __FILE__, __LINE__))
+}	// namespace testspr
+
+#endif	// #ifndef TESTSPR_TRACE_HPP