diff --git a/README.rst b/README.rst
index 8f2831bb..60852c29 100644
--- a/README.rst
+++ b/README.rst
@@ -35,8 +35,8 @@ Supported Compilers
 
 Linux:
 
-* GCC, C++11/14 mode: 4.7.0~4.7.4, 4.8.0~4.8.5, 4.9.0~4.9.3, 5.1.0, 5.2.0
-* Clang, C++11/14 mode: 3.2, 3.3, 3.4~3.4.2, 3.5.0~3.5.1, 3.6.0~3.6.2, 3.7.0
+* GCC, C++11/14 mode: 4.7.0~4.7.4, 4.8.0~4.8.5, 4.9.0~4.9.3, 5.1.0, 5.2.0, 5.3.0
+* Clang, C++11/14 mode: 3.2, 3.3, 3.4~3.4.2, 3.5.0~3.5.1, 3.6.0~3.6.2, 3.7.0~3.7.1
 
 *******************************************************************************
 Author
diff --git a/libs/test/random/test/distribution_generic.hpp b/libs/test/random/test/distribution_generic.hpp
deleted file mode 100644
index aa58e485..00000000
--- a/libs/test/random/test/distribution_generic.hpp
+++ /dev/null
@@ -1,87 +0,0 @@
-#ifndef SPROUT_LIBS_RANDOM_TEST_DISTRIBUTION_GENERIC_HPP
-#define SPROUT_LIBS_RANDOM_TEST_DISTRIBUTION_GENERIC_HPP
-
-#include <string>
-#include <sstream>
-#include <sprout/random/linear_congruential.hpp>
-#include <sprout/random/unique_seed.hpp>
-#include <testspr/tools.hpp>
-
-namespace testspr {
-	template<typename Distribution, typename Engine = sprout::random::minstd_rand0>
-	void random_distribution_test_generic() {
-		using namespace sprout;
-		{
-			SPROUT_STATIC_CONSTEXPR auto parm = typename Distribution::param_type();
-
-			SPROUT_STATIC_CONSTEXPR auto dist1 = Distribution(parm);
-			SPROUT_STATIC_CONSTEXPR auto dist2 = Distribution(parm);
-
-			// min
-			// max
-			TESTSPR_BOTH_ASSERT(dist1.min() <= dist1.max());
-
-			// param
-			TESTSPR_BOTH_ASSERT(parm == dist1.param());
-			{
-				auto dist_temp = Distribution();
-				dist_temp.param(parm);
-				TESTSPR_ASSERT(dist_temp == dist1);
-			}
-
-			// operator==
-			// operator!=
-			TESTSPR_BOTH_ASSERT(dist1 == dist2);
-			TESTSPR_BOTH_ASSERT(!(dist1 != dist2));
-
-			{
-				std::string s;
-
-				// operator<<
-				{
-					std::ostringstream os;
-					os << dist1;
-					// ??? WORKAROUND: for Clang
-#if !defined(__clang__)
-					TESTSPR_ASSERT(!!os);
-#endif
-					s = os.str();
-				}
-
-				auto dist_temp = Distribution();
-
-				// operator>>
-				{
-					std::istringstream is(s);
-					is >> dist_temp;
-					// ??? WORKAROUND: for Clang
-#if !defined(__clang__)
-					TESTSPR_ASSERT(!!is);
-#endif
-				}
-
-				TESTSPR_ASSERT(dist_temp == dist1);
-			}
-
-			// operator()
-			{
-				SPROUT_STATIC_CONSTEXPR auto eng = Engine(SPROUT_UNIQUE_SEED);
-				{
-					SPROUT_STATIC_CONSTEXPR auto rnd = dist1(eng);
-
-					// result
-					TESTSPR_BOTH_ASSERT(dist1.min() <= rnd.result());
-					TESTSPR_BOTH_ASSERT(rnd.result() <= dist1.max());
-
-					// engine
-					TESTSPR_BOTH_ASSERT(rnd.engine().min() <= rnd.engine().max());
-
-					// distribution
-					TESTSPR_BOTH_ASSERT(rnd.distribution().min() <= rnd.distribution().max());
-				}
-			}
-		}
-	}
-}	// namespace testspr
-
-#endif	// #ifndef SPROUT_LIBS_RANDOM_TEST_DISTRIBUTION_GENERIC_HPP
diff --git a/libs/test/random/test/engine_generic.hpp b/libs/test/random/test/engine_generic.hpp
deleted file mode 100644
index b7c2fc0b..00000000
--- a/libs/test/random/test/engine_generic.hpp
+++ /dev/null
@@ -1,73 +0,0 @@
-#ifndef SPROUT_LIBS_RANDOM_TEST_ENGINE_GENERIC_HPP
-#define SPROUT_LIBS_RANDOM_TEST_ENGINE_GENERIC_HPP
-
-#include <string>
-#include <sstream>
-#include <sprout/random/unique_seed.hpp>
-#include <testspr/tools.hpp>
-
-namespace testspr {
-	template<typename Engine>
-	void random_engine_test_generic() {
-		using namespace sprout;
-		{
-			SPROUT_STATIC_CONSTEXPR auto eng1 = Engine(SPROUT_UNIQUE_SEED);
-			SPROUT_STATIC_CONSTEXPR auto eng2 = Engine(SPROUT_UNIQUE_SEED);
-
-			// min
-			// max
-			TESTSPR_BOTH_ASSERT(eng1.min() <= eng1.max());
-
-			// operator==
-			// operator!=
-			TESTSPR_BOTH_ASSERT(eng1 == eng1);
-			TESTSPR_BOTH_ASSERT(!(eng1 == eng2));
-			TESTSPR_BOTH_ASSERT(eng1 != eng2);
-			TESTSPR_BOTH_ASSERT(!(eng1 != eng1));
-
-			{
-				std::string s;
-
-				// operator<<
-				{
-					std::ostringstream os;
-					os << eng1;
-					// ??? WORKAROUND: for Clang
-#if !defined(__clang__)
-					TESTSPR_ASSERT(!!os);
-#endif
-
-					s = os.str();
-				}
-
-				auto eng_temp = Engine();
-
-				// operator>>
-				{
-					std::istringstream is(s);
-					is >> eng_temp;
-					// ??? WORKAROUND: for Clang
-#if !defined(__clang__)
-					TESTSPR_ASSERT(!!is);
-#endif
-				}
-
-				//TESTSPR_ASSERT(eng_temp == eng1);
-			}
-
-			// operator()
-			{
-				SPROUT_STATIC_CONSTEXPR auto rnd = eng1();
-
-				// result
-				TESTSPR_BOTH_ASSERT(eng1.min() <= rnd.result());
-				TESTSPR_BOTH_ASSERT(rnd.result() <= eng1.max());
-
-				// engine
-				TESTSPR_BOTH_ASSERT(rnd.engine().min() <= rnd.engine().max());
-			}
-		}
-	}
-}	// namespace testspr
-
-#endif	// #ifndef SPROUT_LIBS_RANDOM_TEST_ENGINE_GENERIC_HPP
diff --git a/sprout/string/string.hpp b/sprout/string/string.hpp
index a3bdfc39..247c43e6 100644
--- a/sprout/string/string.hpp
+++ b/sprout/string/string.hpp
@@ -691,7 +691,7 @@ namespace sprout {
 		}
 		SPROUT_CONSTEXPR size_type
 		find_first_not_of(value_type const* s, size_type pos, size_type n) const {
-#if SPROUT_GCC_IN_RANGE((5, 1, 0), (5, 3, 0))
+#if SPROUT_GCC_IN_RANGE((5, 1, 0), (5, 4, 0))
 			return sprout::string_detail::find_first_not_of_impl<basic_string>(begin(), size(), sprout::ptr_index(s), pos, n);
 #else
 			return sprout::string_detail::find_first_not_of_impl<basic_string>(begin(), size(), s, pos, n);
@@ -712,7 +712,7 @@ namespace sprout {
 		}
 		SPROUT_CONSTEXPR size_type
 		find_last_not_of(value_type const* s, size_type pos, size_type n) const {
-#if SPROUT_GCC_IN_RANGE((5, 1, 0), (5, 3, 0))
+#if SPROUT_GCC_IN_RANGE((5, 1, 0), (5, 4, 0))
 			return sprout::string_detail::find_last_not_of_impl<basic_string>(begin(), size(), sprout::ptr_index(s), pos, n);
 #else
 			return sprout::string_detail::find_last_not_of_impl<basic_string>(begin(), size(), s, pos, n);