diff --git a/.gitmodules b/.gitmodules
index 94e1d37..1984ae6 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -7,3 +7,6 @@
 [submodule "lib/better-enums"]
 	path = lib/better-enums
 	url = https://github.com/aantron/better-enums
+[submodule "lib/sprout"]
+	path = lib/sprout
+	url = https://github.com/bolero-MURAKAMI/Sprout.git
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8ef6463..2a0e6d6 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -106,6 +106,7 @@ target_compile_features(${PROJECT_NAME}
 target_include_directories(${bare_name}-inc
 	INTERFACE ${PROJECT_BINARY_DIR}
 	INTERFACE ${CMAKE_SOURCE_DIR}/include
+	INTERFACE ${CMAKE_SOURCE_DIR}/lib/sprout
 )
 
 
diff --git a/include/helpers/lexical_cast.hpp b/include/helpers/lexical_cast.hpp
index 7417892..f5bced8 100644
--- a/include/helpers/lexical_cast.hpp
+++ b/include/helpers/lexical_cast.hpp
@@ -21,10 +21,12 @@
 #include "compatibility.h"
 #include "helpers/sequence_bt.hpp"
 #include "helpers/MaxSizedArray.hpp"
+#include "sprout/math/log10.hpp"
+#include "sprout/math/log2.hpp"
+#include "sprout/math/pow.hpp"
 #include <type_traits>
 #include <utility>
 #include <limits>
-#include <cmath>
 #include <cstdint>
 #include <algorithm>
 #include <string>
@@ -112,7 +114,7 @@ namespace dinhelp {
 			static std::size_t count_digits ( T parValue ) a_pure;
 			static typename std::make_unsigned<T>::type make_unsigned ( T parValue ) a_pure;
 			static constexpr std::size_t count_digits_bt (std::size_t parNum) {
-				return (parNum == 0 ? 0 : static_cast<std::size_t>(std::log10(static_cast<double>(parNum)) / std::log10(static_cast<double>(base)))) + 1;
+				return (parNum == 0 ? 0 : static_cast<std::size_t>(sprout::log10(static_cast<double>(parNum)) / sprout::log10(static_cast<double>(base)))) + 1;
 			}
 		};
 	} //namespace implem
@@ -133,7 +135,7 @@ namespace dinhelp {
 
 			static typename std::make_unsigned<T>::type make_unsigned ( T parValue ) a_pure;
 			static constexpr std::size_t count_digits_bt (std::size_t parNum) {
-				return (parNum == 0 ? 0 : static_cast<std::size_t>(std::log10(static_cast<double>(parNum)))) + 1 + (std::numeric_limits<T>::is_signed ? 1 : 0);
+				return (parNum == 0 ? 0 : static_cast<std::size_t>(sprout::log10(static_cast<double>(parNum)))) + 1 + (std::numeric_limits<T>::is_signed ? 1 : 0);
 			}
 		};
 
@@ -153,7 +155,7 @@ namespace dinhelp {
 			static std::size_t count_digits ( T parValue ) a_pure;
 			static typename std::make_unsigned<T>::type make_unsigned ( T parValue ) a_pure;
 			static constexpr std::size_t count_digits_bt (std::size_t parNum) {
-				return (parNum == 0 ? 0 : static_cast<std::size_t>(std::log2(static_cast<double>(parNum)))) + 1;
+				return (parNum == 0 ? 0 : static_cast<std::size_t>(sprout::log2(static_cast<double>(parNum)))) + 1;
 			}
 		};
 
@@ -163,7 +165,7 @@ namespace dinhelp {
 		std::size_t dec<T>::count_digits_implem (T parValue, dinhelp::bt::index_seq<Powers...>, dinhelp::bt::index_seq<Digits...>) {
 			typedef typename std::make_unsigned<T>::type UT;
 			static constexpr UT powers[] = { 0, static_cast<UT>(dinhelp::implem::power<10, Powers + 1>::value)... };
-			static constexpr std::size_t maxdigits[] = { count_digits_bt(static_cast<std::size_t>(::pow(2.0, Digits))) - (std::numeric_limits<T>::is_signed ? 1 : 0)... };
+			static constexpr std::size_t maxdigits[] = { count_digits_bt(static_cast<std::size_t>(sprout::pow(2.0, Digits))) - (std::numeric_limits<T>::is_signed ? 1 : 0)... };
 			const auto bits = sizeof(parValue) * CHAR_BIT - dinhelp::implem::count_leading_zeroes<T>(dinhelp::implem::abs(parValue));
 			static_assert(std::is_same<UT, decltype(dinhelp::implem::abs(parValue))>::value, "Unexpected type");
 			return (dinhelp::implem::abs(parValue) < powers[maxdigits[bits] - 1] ? maxdigits[bits] - 1 : maxdigits[bits]) + dinhelp::implem::is_negative<T>::check(parValue);
diff --git a/lib/sprout b/lib/sprout
new file mode 160000
index 0000000..fea5e75
--- /dev/null
+++ b/lib/sprout
@@ -0,0 +1 @@
+Subproject commit fea5e752bda763c27ecd6f84531cdd0b4f82399d
diff --git a/src/backends/redis/async_connection.cpp b/src/backends/redis/async_connection.cpp
index cf48a01..483bc3c 100644
--- a/src/backends/redis/async_connection.cpp
+++ b/src/backends/redis/async_connection.cpp
@@ -36,13 +36,18 @@ namespace redis {
 			ev_break(parLoop, EVBREAK_ALL);
 		}
 
-		void lock_mutex_libev (ev_loop* parLoop) {
+		void lock_mutex_libev (ev_loop* parLoop) noexcept {
 			std::mutex* mtx = static_cast<std::mutex*>(ev_userdata(parLoop));
 			assert(mtx);
-			mtx->lock();
+			try {
+				mtx->lock();
+			}
+			catch (const std::system_error&) {
+				assert(false);
+			}
 		}
 
-		void unlock_mutex_libev (ev_loop* parLoop) {
+		void unlock_mutex_libev (ev_loop* parLoop) noexcept {
 			std::mutex* mtx = static_cast<std::mutex*>(ev_userdata(parLoop));
 			assert(mtx);
 			mtx->unlock();