Index: build/autotools/configure.ac
===================================================================
--- build/autotools/configure.ac	(revision 11987)
+++ build/autotools/configure.ac	(working copy)
@@ -288,13 +288,14 @@
 AC_PROG_CC_STDC
 #AC_PROG_CC_C99
 
-# We need C++14 support
-AX_CXX_COMPILE_STDCXX(17, [noext], [optional])
-AS_IF([test "x$HAVE_CXX17" != "x1"],
- [
-  AX_CXX_COMPILE_STDCXX(14, [noext], [mandatory])
- ],[]
-)
+# We need C++17 support
+#AX_CXX_COMPILE_STDCXX(20, [noext], [optional])
+#AS_IF([test "x$HAVE_CXX20" != "x1"],
+# [
+#  AX_CXX_COMPILE_STDCXX(17, [noext], [mandatory])
+# ],[]
+#)
+AX_CXX_COMPILE_STDCXX(17, [noext], [mandatory])
 
 AC_LANG_PUSH([C])
 AX_CHECK_COMPILE_FLAG([-fvisibility=hidden], [CFLAGS="$CFLAGS -fvisibility=hidden"])
Index: build/make/config-afl.mk
===================================================================
--- build/make/config-afl.mk	(revision 11987)
+++ build/make/config-afl.mk	(working copy)
@@ -9,12 +9,8 @@
 else
 ifeq ($(shell printf '\n' > bin/empty.cpp ; if $(CXX) -std=c++17 -c bin/empty.cpp -o bin/empty.out > /dev/null 2>&1 ; then echo 'c++17' ; fi ), c++17)
 CXXFLAGS_STDCXX = -std=c++17
-else
-ifeq ($(shell printf '\n' > bin/empty.cpp ; if $(CXX) -std=c++14 -c bin/empty.cpp -o bin/empty.out > /dev/null 2>&1 ; then echo 'c++14' ; fi ), c++14)
-CXXFLAGS_STDCXX = -std=c++14
 endif
 endif
-endif
 CFLAGS_STDC = -std=c99
 CXXFLAGS += $(CXXFLAGS_STDCXX)
 CFLAGS += $(CFLAGS_STDC)
Index: build/make/config-djgpp.mk
===================================================================
--- build/make/config-djgpp.mk	(revision 11987)
+++ build/make/config-djgpp.mk	(working copy)
@@ -6,7 +6,7 @@
 
 # Note that we are using GNU extensions instead of 100% standards-compliant
 # mode, because otherwise DJGPP-specific headers/functions are unavailable.
-CXXFLAGS_STDCXX = -std=gnu++14
+CXXFLAGS_STDCXX = -std=gnu++17
 CFLAGS_STDC = -std=gnu99
 CXXFLAGS += $(CXXFLAGS_STDCXX)
 CFLAGS += $(CFLAGS_STDC)
Index: build/make/config-emscripten.mk
===================================================================
--- build/make/config-emscripten.mk	(revision 11987)
+++ build/make/config-emscripten.mk	(working copy)
@@ -11,12 +11,8 @@
 else
 ifeq ($(shell printf '\n' > bin/empty.cpp ; if $(CXX) -std=c++17 -c bin/empty.cpp -o bin/empty.out > /dev/null 2>&1 ; then echo 'c++17' ; fi ), c++17)
 CXXFLAGS_STDCXX = -std=c++17
-else
-ifeq ($(shell printf '\n' > bin/empty.cpp ; if $(CXX) -std=c++14 -c bin/empty.cpp -o bin/empty.out > /dev/null 2>&1 ; then echo 'c++14' ; fi ), c++14)
-CXXFLAGS_STDCXX = -std=c++14
 endif
 endif
-endif
 CFLAGS_STDC = -std=c99
 CXXFLAGS += $(CXXFLAGS_STDCXX)
 CFLAGS += $(CFLAGS_STDC)
Index: build/make/config-gcc.mk
===================================================================
--- build/make/config-gcc.mk	(revision 11987)
+++ build/make/config-gcc.mk	(working copy)
@@ -9,12 +9,8 @@
 else
 ifeq ($(shell printf '\n' > bin/empty.cpp ; if $(CXX) -std=c++17 -c bin/empty.cpp -o bin/empty.out > /dev/null 2>&1 ; then echo 'c++17' ; fi ), c++17)
 CXXFLAGS_STDCXX = -std=c++17
-else
-ifeq ($(shell printf '\n' > bin/empty.cpp ; if $(CXX) -std=c++14 -c bin/empty.cpp -o bin/empty.out > /dev/null 2>&1 ; then echo 'c++14' ; fi ), c++14)
-CXXFLAGS_STDCXX = -std=c++14
 endif
 endif
-endif
 CFLAGS_STDC = -std=c99
 CXXFLAGS += $(CXXFLAGS_STDCXX)
 CFLAGS += $(CFLAGS_STDC)
Index: build/make/config-generic.mk
===================================================================
--- build/make/config-generic.mk	(revision 11987)
+++ build/make/config-generic.mk	(working copy)
@@ -4,7 +4,7 @@
 LD  ?= c++
 AR  = ar
 
-CXXFLAGS_STDCXX = -std=c++14
+CXXFLAGS_STDCXX = -std=c++17
 CFLAGS_STDC = -std=c99
 CXXFLAGS += $(CXXFLAGS_STDCXX)
 CFLAGS += $(CFLAGS_STDC)
Index: build/make/config-mingw64-win32.mk
===================================================================
--- build/make/config-mingw64-win32.mk	(revision 11987)
+++ build/make/config-mingw64-win32.mk	(working copy)
@@ -4,7 +4,7 @@
 LD  = i686-w64-mingw32-g++$(MINGW_FLAVOUR)
 AR  = i686-w64-mingw32-ar$(MINGW_FLAVOUR)
 
-CXXFLAGS_STDCXX = -std=c++14
+CXXFLAGS_STDCXX = -std=c++17
 CFLAGS_STDC = -std=c99
 CXXFLAGS += $(CXXFLAGS_STDCXX)
 CFLAGS += $(CFLAGS_STDC)
Index: build/make/config-mingw64-win64.mk
===================================================================
--- build/make/config-mingw64-win64.mk	(revision 11987)
+++ build/make/config-mingw64-win64.mk	(working copy)
@@ -4,7 +4,7 @@
 LD  = x86_64-w64-mingw32-g++$(MINGW_FLAVOUR)
 AR  = x86_64-w64-mingw32-ar$(MINGW_FLAVOUR)
 
-CXXFLAGS_STDCXX = -std=c++14
+CXXFLAGS_STDCXX = -std=c++17
 CFLAGS_STDC = -std=c99
 CXXFLAGS += $(CXXFLAGS_STDCXX)
 CFLAGS += $(CFLAGS_STDC)
Index: build/make/config-mingw64-winrt-amd64.mk
===================================================================
--- build/make/config-mingw64-winrt-amd64.mk	(revision 11987)
+++ build/make/config-mingw64-winrt-amd64.mk	(working copy)
@@ -4,7 +4,7 @@
 LD  = x86_64-w64-mingw32-g++$(MINGW_FLAVOUR)
 AR  = x86_64-w64-mingw32-ar$(MINGW_FLAVOUR)
 
-CXXFLAGS_STDCXX = -std=c++14
+CXXFLAGS_STDCXX = -std=c++17
 CFLAGS_STDC = -std=c99
 CXXFLAGS += $(CXXFLAGS_STDCXX)
 CFLAGS += $(CFLAGS_STDC)
Index: build/make/config-mingw64-winrt-x86.mk
===================================================================
--- build/make/config-mingw64-winrt-x86.mk	(revision 11987)
+++ build/make/config-mingw64-winrt-x86.mk	(working copy)
@@ -4,7 +4,7 @@
 LD  = i686-w64-mingw32-g++$(MINGW_FLAVOUR)
 AR  = i686-w64-mingw32-ar$(MINGW_FLAVOUR)
 
-CXXFLAGS_STDCXX = -std=c++14
+CXXFLAGS_STDCXX = -std=c++17
 CFLAGS_STDC = -std=c99
 CXXFLAGS += $(CXXFLAGS_STDCXX)
 CFLAGS += $(CFLAGS_STDC)
Index: build/make/config-standard.mk
===================================================================
--- build/make/config-standard.mk	(revision 11987)
+++ build/make/config-standard.mk	(working copy)
@@ -4,7 +4,7 @@
 LD  ?= c++
 AR  = ar
 
-CXXFLAGS_STDCXX = -std=c++14
+CXXFLAGS_STDCXX = -std=c++17
 CFLAGS_STDC = -std=c99
 CXXFLAGS += $(CXXFLAGS_STDCXX)
 CFLAGS += $(CFLAGS_STDC)
Index: build/pch/PCH.h
===================================================================
--- build/pch/PCH.h	(revision 11987)
+++ build/pch/PCH.h	(working copy)
@@ -111,9 +111,7 @@
 #include <thread>
 #include <type_traits>
 #include <utility>
-#if MPT_CXX_AT_LEAST(17)
 #include <variant>
-#endif // C++17
 #include <vector>
 
 
Index: common/BuildSettings.h
===================================================================
--- common/BuildSettings.h	(revision 11987)
+++ common/BuildSettings.h	(working copy)
@@ -530,11 +530,7 @@
 #define MPT_ENABLE_TEMPFILE
 #endif
 
-#if MPT_CXX_AT_LEAST(17) && defined(MPT_CHARSET_CODECVTUTF8)
-#undef MPT_CHARSET_CODECVTUTF8 // std::codecvt_utf8 is deprecated in c++17
-#endif
-
-#if !defined(MPT_CHARSET_WIN32) && !defined(MPT_CHARSET_ICONV) && !defined(MPT_CHARSET_CODECVTUTF8) && !defined(MPT_CHARSET_INTERNAL)
+#if !defined(MPT_CHARSET_WIN32) && !defined(MPT_CHARSET_ICONV) && !defined(MPT_CHARSET_INTERNAL)
 #define MPT_CHARSET_INTERNAL
 #endif
 
@@ -741,15 +737,13 @@
 
 // standard library quirks
 
-#if MPT_CXX_AT_LEAST(17)
 #if (MPT_COMPILER_GCC || MPT_COMPILER_CLANG)
 // we need to detect the standard library via macro __GLIBCXX__
 #include <vector>
 #endif
-#if MPT_COMPILER_MSVC || MPT_GCC_BEFORE(8,1,0) || MPT_CLANG_BEFORE(5,0,0) || (MPT_COMPILER_GCC && defined(__GLIBCXX__) && (defined(__MINGW32__) || defined(__MINGW64__))) || (MPT_COMPILER_CLANG && defined(__GLIBCXX__)) || (MPT_COMPILER_CLANG && MPT_OS_MACOSX_OR_IOS) || MPT_OS_OPENBSD || MPT_OS_EMSCRIPTEN || MPT_OS_HAIKU || (defined(__clang__) && defined(_MSC_VER))
+#if MPT_COMPILER_MSVC || MPT_GCC_BEFORE(8,1,0) || (MPT_COMPILER_GCC && defined(__GLIBCXX__) && (defined(__MINGW32__) || defined(__MINGW64__))) || (MPT_COMPILER_CLANG && defined(__GLIBCXX__)) || (MPT_COMPILER_CLANG && MPT_OS_MACOSX_OR_IOS) || MPT_OS_OPENBSD || MPT_OS_EMSCRIPTEN || MPT_OS_HAIKU || (defined(__clang__) && defined(_MSC_VER))
 #define MPT_COMPILER_QUIRK_NO_ALIGNEDALLOC
 #endif
-#endif
 
 
 
Index: common/CompilerDetect.h
===================================================================
--- common/CompilerDetect.h	(revision 11987)
+++ common/CompilerDetect.h	(working copy)
@@ -34,8 +34,8 @@
 #define MPT_CLANG_AT_LEAST(major,minor,patch)        (MPT_COMPILER_CLANG_VERSION >= MPT_COMPILER_MAKE_VERSION3((major),(minor),(patch)))
 #define MPT_CLANG_BEFORE(major,minor,patch)          (MPT_COMPILER_CLANG_VERSION <  MPT_COMPILER_MAKE_VERSION3((major),(minor),(patch)))
 
-#if MPT_CLANG_BEFORE(3,8,0)
-#error "clang version 3.8 required"
+#if MPT_CLANG_BEFORE(5,0,0)
+#error "clang version 5 required"
 #endif
 
 #if defined(__clang_analyzer__)
@@ -51,8 +51,8 @@
 #define MPT_GCC_AT_LEAST(major,minor,patch)          (MPT_COMPILER_GCC_VERSION >= MPT_COMPILER_MAKE_VERSION3((major),(minor),(patch)))
 #define MPT_GCC_BEFORE(major,minor,patch)            (MPT_COMPILER_GCC_VERSION <  MPT_COMPILER_MAKE_VERSION3((major),(minor),(patch)))
 
-#if MPT_GCC_BEFORE(5,1,0)
-#error "GCC version 5.1 required"
+#if MPT_GCC_BEFORE(7,1,0)
+#error "GCC version 7.1 required"
 #endif
 
 #elif defined(_MSC_VER)
@@ -139,10 +139,8 @@
 
 #if (__cplusplus >= 201703)
 #define MPT_CXX 17
-#elif (__cplusplus >= 201402)
-#define MPT_CXX 14
 #else
-#define MPT_CXX 14
+#define MPT_CXX 17
 #endif
 
 #elif MPT_COMPILER_MSVC
@@ -149,15 +147,13 @@
 
 #if (_MSVC_LANG >= 201703)
 #define MPT_CXX 17
-#elif (_MSVC_LANG >= 201402)
-#define MPT_CXX 14
 #else
-#define MPT_CXX 14
+#define MPT_CXX 17
 #endif
 
 #else
 
-#define MPT_CXX 14
+#define MPT_CXX 17
 
 #endif
 
@@ -308,11 +304,6 @@
 #endif
 
 
-#if MPT_GCC_BEFORE(6,1,0)
-#define MPT_COMPILER_QUIRK_NO_CONSTEXPR14_THROW
-#endif
-
-
 #if defined(__arm__)
 
 #if defined(__SOFTFP__)
Index: common/mptAlloc.cpp
===================================================================
--- common/mptAlloc.cpp	(revision 11987)
+++ common/mptAlloc.cpp	(working copy)
@@ -39,28 +39,9 @@
 
 
 
-#if MPT_CXX_AT_LEAST(17)
-#else
-void* align(std::size_t alignment, std::size_t size, void* &ptr, std::size_t &space) noexcept
-{
-	std::size_t offset = static_cast<std::size_t>(reinterpret_cast<std::uintptr_t>(ptr) & (alignment - 1));
-	if(offset != 0)
-	{
-		offset = alignment - offset;
-	}
-	if((space < offset) || ((space - offset) < size))
-	{
-		return nullptr;
-	}
-	ptr = static_cast<mpt::byte*>(ptr) + offset;
-	space -= offset;
-	return ptr;
-}
-#endif
-
 aligned_raw_memory aligned_alloc_impl(std::size_t size, std::size_t count, std::size_t alignment)
 {
-	#if MPT_CXX_AT_LEAST(17) && !defined(MPT_COMPILER_QUIRK_NO_ALIGNEDALLOC)
+	#if !defined(MPT_COMPILER_QUIRK_NO_ALIGNEDALLOC)
 		std::size_t space = count * size;
 		void* mem = std::aligned_alloc(alignment, space);
 		if(!mem)
@@ -86,7 +67,7 @@
 				MPT_EXCEPTION_THROW_OUT_OF_MEMORY();
 			}
 			void* aligned_mem = mem;
-			void* aligned = mpt::align(alignment, size * count, aligned_mem, space);
+			void* aligned = std::align(alignment, size * count, aligned_mem, space);
 			if(!aligned)
 			{
 				MPT_EXCEPTION_THROW_OUT_OF_MEMORY();
@@ -107,7 +88,7 @@
 
 void aligned_free(aligned_raw_memory raw)
 {
-	#if MPT_CXX_AT_LEAST(17) && !defined(MPT_COMPILER_QUIRK_NO_ALIGNEDALLOC)
+	#if !defined(MPT_COMPILER_QUIRK_NO_ALIGNEDALLOC)
 		std::free(raw.mem);
 	#elif MPT_COMPILER_MSVC || (defined(__clang__) && defined(_MSC_VER))
 		_aligned_free(raw.mem);
Index: common/mptAlloc.h
===================================================================
--- common/mptAlloc.h	(revision 11987)
+++ common/mptAlloc.h	(working copy)
@@ -88,7 +88,7 @@
 
 
 
-#if MPT_CXX_AT_LEAST(17) && !(MPT_COMPILER_CLANG && defined(__GLIBCXX__)) && !(MPT_COMPILER_CLANG && MPT_OS_MACOSX_OR_IOS)
+#if !(MPT_COMPILER_CLANG && defined(__GLIBCXX__)) && !(MPT_COMPILER_CLANG && MPT_OS_MACOSX_OR_IOS)
 using std::launder;
 #else
 template <class T>
@@ -99,15 +99,7 @@
 #endif
 
 
-#if MPT_CXX_AT_LEAST(17)
-using std::align;
-#else
-// pre-C++17, std::align does not support over-alignement
-void* align(std::size_t alignment, std::size_t size, void* &ptr, std::size_t &space) noexcept;
-#endif
 
-
-
 struct aligned_raw_memory
 {
 	void* aligned;
Index: common/mptAssert.h
===================================================================
--- common/mptAssert.h	(revision 11987)
+++ common/mptAssert.h	(working copy)
@@ -138,11 +138,7 @@
 
 #define MPT_CONSTEXPR11_ASSERT MPT_STATIC_ASSERT
 #define MPT_CONSTEXPR14_ASSERT MPT_STATIC_ASSERT
-#if MPT_CXX_AT_LEAST(17)
 #define MPT_CONSTEXPR17_ASSERT MPT_STATIC_ASSERT
-#else
-#define MPT_CONSTEXPR17_ASSERT MPT_ASSERT
-#endif
 
 
 
Index: common/mptBaseMacros.h
===================================================================
--- common/mptBaseMacros.h	(revision 11987)
+++ common/mptBaseMacros.h	(working copy)
@@ -29,11 +29,7 @@
 
 
 // Compile time assert.
-#if MPT_CXX_AT_LEAST(17)
 #define MPT_STATIC_ASSERT static_assert
-#else
-#define MPT_STATIC_ASSERT(expr) static_assert((expr), "compile time assertion failed: " #expr)
-#endif
 // legacy
 #define STATIC_ASSERT(x) MPT_STATIC_ASSERT(x)
 
@@ -58,62 +54,22 @@
 #define MPT_CONSTEXPR11_VAR constexpr
 #define MPT_CONSTEXPR14_FUN constexpr MPT_FORCEINLINE
 #define MPT_CONSTEXPR14_VAR constexpr
-#if MPT_CXX_AT_LEAST(17)
 #define MPT_CONSTEXPR17_FUN constexpr MPT_FORCEINLINE
 #define MPT_CONSTEXPR17_VAR constexpr
-#else
-#define MPT_CONSTEXPR17_FUN MPT_FORCEINLINE
-#define MPT_CONSTEXPR17_VAR const
-#endif
 
 namespace mpt
 {
-#if MPT_CXX_AT_LEAST(17)
 template <auto V> struct constant_value { static constexpr decltype(V) value() { return V; } };
 #define MPT_FORCE_CONSTEXPR(expr) (mpt::constant_value<( expr )>::value())
-#else
-template <typename T, T V> struct constant_value_helper { static constexpr T value() { return V; } };
-#define MPT_FORCE_CONSTEXPR(expr) (mpt::constant_value_helper<decltype( expr ), ( expr )>::value())
-#endif
 }  // namespace mpt
 
 
 
 // C++17 std::size and std::data
-#if MPT_CXX_AT_LEAST(17)
 namespace mpt {
 using std::size;
 using std::data;
 } // namespace mpt
-#else
-namespace mpt {
-template <typename T>
-MPT_CONSTEXPR11_FUN auto size(const T & v) -> decltype(v.size())
-{
-	return v.size();
-}
-template <typename T, std::size_t N>
-MPT_CONSTEXPR11_FUN std::size_t size(const T(&)[N]) noexcept
-{
-	return N;
-}
-template <typename T>
-MPT_CONSTEXPR11_FUN auto data(const T & v) -> decltype(v.data())
-{
-	return v.data();
-}
-template <typename T>
-MPT_CONSTEXPR11_FUN auto data(T & v) -> decltype(v.data())
-{
-	return v.data();
-}
-template <typename T, std::size_t N>
-MPT_CONSTEXPR11_FUN T* data(T(&a)[N]) noexcept
-{
-	return a;
-}
-} // namespace mpt
-#endif
 // legacy
 #if MPT_COMPILER_MSVC
 OPENMPT_NAMESPACE_END
@@ -137,29 +93,14 @@
 
 
 
-#if MPT_CXX_AT_LEAST(17)
-#define MPT_NODISCARD [[nodiscard]]
+#define MPT_ATTR_NODISCARD [[nodiscard]]
 #define MPT_DISCARD(expr) static_cast<void>(expr)
-#else
-#define MPT_NODISCARD
-#define MPT_DISCARD(expr) expr
-#endif
 
 
 
-#if MPT_CXX_AT_LEAST(17)
 #define MPT_CONSTANT_IF if constexpr
-#endif
 
 #if MPT_COMPILER_MSVC
-#if !defined(MPT_CONSTANT_IF)
-#define MPT_CONSTANT_IF(x) \
-  __pragma(warning(push)) \
-  __pragma(warning(disable:4127)) \
-  if(x) \
-  __pragma(warning(pop)) \
-/**/
-#endif
 #define MPT_MAYBE_CONSTANT_IF(x) \
   __pragma(warning(push)) \
   __pragma(warning(disable:4127)) \
@@ -188,11 +129,6 @@
 /**/
 #endif
 
-#if !defined(MPT_CONSTANT_IF)
-// MPT_CONSTANT_IF disables compiler warnings for conditions that are either always true or always false for some reason (dependent on template arguments for example)
-#define MPT_CONSTANT_IF(x) if(x)
-#endif
-
 #if !defined(MPT_MAYBE_CONSTANT_IF)
 // MPT_MAYBE_CONSTANT_IF disables compiler warnings for conditions that may in some case be either always false or always true (this may turn out to be useful in ASSERTions in some cases).
 #define MPT_MAYBE_CONSTANT_IF(x) if(x)
@@ -228,23 +164,7 @@
 
 
 // Macro for marking intentional fall-throughs in switch statements - can be used for static analysis if supported.
-#if MPT_CXX_AT_LEAST(17)
-	#define MPT_FALLTHROUGH [[fallthrough]]
-#elif MPT_COMPILER_MSVC
-	#define MPT_FALLTHROUGH __fallthrough
-#elif MPT_COMPILER_CLANG
-	#define MPT_FALLTHROUGH [[clang::fallthrough]]
-#elif MPT_COMPILER_GCC && MPT_GCC_AT_LEAST(7,1,0)
-	#define MPT_FALLTHROUGH __attribute__((fallthrough))
-#elif defined(__has_cpp_attribute)
-	#if __has_cpp_attribute(fallthrough)
-		#define MPT_FALLTHROUGH [[fallthrough]]
-	#else
-		#define MPT_FALLTHROUGH MPT_DO { } MPT_WHILE_0
-	#endif
-#else
-	#define MPT_FALLTHROUGH MPT_DO { } MPT_WHILE_0
-#endif
+#define MPT_FALLTHROUGH [[fallthrough]]
 
 
 
Index: common/mptBaseTypes.h
===================================================================
--- common/mptBaseTypes.h	(revision 11987)
+++ common/mptBaseTypes.h	(working copy)
@@ -191,20 +191,10 @@
 
 MPT_STATIC_ASSERT(sizeof(char) == 1);
 
-#if MPT_CXX_AT_LEAST(17)
 namespace mpt {
 using byte = std::byte;
 } // namespace mpt
 #define MPT_BYTE_IS_STD_BYTE 1
-#else
-// In C++11 and C++14, a C++17 compatible definition of byte would not be required to be allowed to alias other types,
-// thus just use a typedef for unsigned char which is guaranteed to be allowed to alias.
-//enum class byte : unsigned char { };
-namespace mpt {
-using byte = unsigned char;
-} // namespace mpt
-#define MPT_BYTE_IS_STD_BYTE 0
-#endif
 MPT_STATIC_ASSERT(sizeof(mpt::byte) == 1);
 MPT_STATIC_ASSERT(alignof(mpt::byte) == 1);
 
Index: common/mptBaseUtils.h
===================================================================
--- common/mptBaseUtils.h	(revision 11987)
+++ common/mptBaseUtils.h	(working copy)
@@ -67,9 +67,7 @@
 
 namespace mpt
 {
-// Work-around for GCC5, which does not allow throw statements in constexpr functions, but only throw expressions inside ternary ? operator.
-// And also work-around for a simpler, MPT_COMPILER_QUIRK_NO_CONSTEXPR14_THROW-dependent work-around, which would have thrown in a separate constexpr function,
-// which however is not allowed due to the requirement of at least 1 non-throwing function argument combination in C++ (14,17,2a) (and thus all other compilers).
+// Work-around for the requirement of at least 1 non-throwing function argument combination in C++ (17,2a).
 template <typename Exception>
 MPT_CONSTEXPR14_FUN bool constexpr_throw_helper(Exception && e, bool really = true)
 {
@@ -432,29 +430,8 @@
 
 namespace mpt
 {
-
 // C++17 clamp
-
-#if MPT_CXX_AT_LEAST(17)
-
 using std::clamp;
-
-#else
-
-template<typename T, typename Compare>
-MPT_CONSTEXPR11_FUN const T & clamp(const T & v, const T & lo, const T & hi, Compare comp)
-{
-	return comp(v, lo) ? lo : comp(hi, v) ? hi : v;
-}
-
-template<typename T>
-MPT_CONSTEXPR11_FUN const T & clamp(const T & v, const T & lo, const T & hi)
-{
-	return mpt::clamp(v, lo, hi, std::less<T>());
-}
-
-#endif
-
 } // namespace mpt
 
 
@@ -706,54 +683,8 @@
 
 namespace mpt
 {
-
-#if MPT_CXX_AT_LEAST(17)
-
 using std::gcd;
 using std::lcm;
-
-#else
-
-	// Greatest Common Divisor. Always returns non-negative number.
-	// compatible with C++17 std::gcd
-	template <typename A, typename B>
-	inline typename std::common_type<A, B>::type gcd(A a_, B b_)
-	{
-		typename std::common_type<A, B>::type a = a_;
-		typename std::common_type<A, B>::type b = b_;
-		if(a < 0)
-			a = -a;
-		if(b < 0)
-			b = -b;
-		for(;;)
-		{
-			if(a == 0)
-				return b;
-			b %= a;
-			if(b == 0)
-				return a;
-			a %= b;
-		}
-	}
-
-	// Least Common Multiple. Always returns non-negative number.
-	// compatible with C++17 std::lcm
-	template <typename A, typename B>
-	inline typename std::common_type<A, B>::type lcm(A a_, B b_)
-	{
-		typename std::common_type<A, B>::type a = a_;
-		typename std::common_type<A, B>::type b = b_;
-		if(a < 0)
-			a = -a;
-		if(b < 0)
-			b = -b;
-		if((a | b) == 0)
-			return 0;
-		return a / mpt::gcd(a, b) * b;
-	}
-
-#endif
-
 } // namespace mpt
 
 
Index: common/mptString.cpp
===================================================================
--- common/mptString.cpp	(revision 11987)
+++ common/mptString.cpp	(working copy)
@@ -12,9 +12,6 @@
 
 #include "Endianness.h"
 
-#if defined(MPT_CHARSET_CODECVTUTF8)
-#include <codecvt>
-#endif
 #if defined(MPT_CHARSET_INTERNAL) || defined(MPT_CHARSET_WIN32)
 #include <cstdlib>
 #endif
@@ -332,7 +329,7 @@
 };
 */
 
-#if defined(MPT_CHARSET_CODECVTUTF8) || defined(MPT_CHARSET_INTERNAL) || defined(MPT_CHARSET_WIN32)
+#if defined(MPT_CHARSET_INTERNAL) || defined(MPT_CHARSET_WIN32)
 
 static const uint32 CharsetTableISO8859_15[256] = {
 	0x0000,0x0001,0x0002,0x0003,0x0004,0x0005,0x0006,0x0007,0x0008,0x0009,0x000a,0x000b,0x000c,0x000d,0x000e,0x000f,
@@ -391,7 +388,7 @@
 	0x2261,0x00b1,0x2265,0x2264,0x2320,0x2321,0x00f7,0x2248,0x00b0,0x2219,0x00b7,0x221a,0x207f,0x00b2,0x25a0,0x00a0
 };
 
-#endif // MPT_CHARSET_CODECVTUTF8 || MPT_CHARSET_INTERNAL || MPT_CHARSET_WIN32
+#endif // MPT_CHARSET_INTERNAL || MPT_CHARSET_WIN32
 
 
 #define C(x) (static_cast<uint8>((x)))
@@ -510,7 +507,7 @@
 	return res;
 }
 
-#if defined(MPT_CHARSET_CODECVTUTF8) || defined(MPT_CHARSET_INTERNAL) || defined(MPT_CHARSET_WIN32)
+#if defined(MPT_CHARSET_INTERNAL) || defined(MPT_CHARSET_WIN32)
 
 static widestring FromAscii(const std::string &str, widechar replacement = wide_default_replacement)
 {
@@ -828,26 +825,8 @@
 
 #endif // MPT_ENABLE_CHARSET_LOCALE && !MPT_LOCALE_ASSUME_CHARSET
 
-#endif // MPT_CHARSET_CODECVTUTF8 || MPT_CHARSET_INTERNAL || MPT_CHARSET_WIN32
+#endif // MPT_CHARSET_INTERNAL || MPT_CHARSET_WIN32
 
-#if defined(MPT_CHARSET_CODECVTUTF8)
-
-static std::wstring FromUTF8(const std::string &str, wchar_t replacement = L'\uFFFD')
-{
-	MPT_UNREFERENCED_PARAMETER(replacement);
-	std::wstring_convert<std::codecvt_utf8<wchar_t> > conv;
-	return conv.from_bytes(str);
-}
-
-static std::string ToUTF8(const std::wstring &str, char replacement = '?')
-{
-	MPT_UNREFERENCED_PARAMETER(replacement);
-	std::wstring_convert<std::codecvt_utf8<wchar_t> > conv;
-	return conv.to_bytes(str);
-}
-
-#endif // MPT_CHARSET_CODECVTUTF8
-
 #if defined(MPT_CHARSET_INTERNAL) || defined(MPT_CHARSET_WIN32)
 
 static widestring FromUTF8(const std::string &str, widechar replacement = wide_default_replacement)
@@ -1175,16 +1154,10 @@
 		{
 			return Tdststring();
 		}
-		#if MPT_CXX_AT_LEAST(17)
-			Tdststring encoded_string(required_size, char());
-			WideCharToMultiByte(codepage, 0, src.c_str(), -1, encoded_string.data(), required_size, nullptr, nullptr);
-			encoded_string.resize(encoded_string.size() - 1); // remove \0
-			return encoded_string;
-		#else
-			std::vector<CHAR> encoded_string(required_size);
-			WideCharToMultiByte(codepage, 0, src.c_str(), -1, encoded_string.data(), required_size, nullptr, nullptr);
-			return reinterpret_cast<const typename Tdststring::value_type*>(encoded_string.data());
-		#endif
+		Tdststring encoded_string(required_size, char());
+		WideCharToMultiByte(codepage, 0, src.c_str(), -1, encoded_string.data(), required_size, nullptr, nullptr);
+		encoded_string.resize(encoded_string.size() - 1); // remove \0
+		return encoded_string;
 	#elif defined(MPT_CHARSET_ICONV)
 		iconv_t conv = iconv_t();
 		conv = iconv_open(CharsetToStringTranslit(charset), Charset_wchar_t());
@@ -1302,16 +1275,10 @@
 		{
 			return widestring();
 		}
-		#if MPT_CXX_AT_LEAST(17)
-			widestring decoded_string(required_size, widechar());
-			MultiByteToWideChar(codepage, 0, reinterpret_cast<const char*>(src.c_str()), -1, decoded_string.data(), required_size);
-			decoded_string.resize(decoded_string.size() - 1); // remove \0
-			return decoded_string;
-		#else
-			std::vector<WCHAR> decoded_string(required_size);
-			MultiByteToWideChar(codepage, 0, reinterpret_cast<const char*>(src.c_str()), -1, decoded_string.data(), required_size);
-			return decoded_string.data();
-		#endif
+		widestring decoded_string(required_size, widechar());
+		MultiByteToWideChar(codepage, 0, reinterpret_cast<const char*>(src.c_str()), -1, decoded_string.data(), required_size);
+		decoded_string.resize(decoded_string.size() - 1); // remove \0
+		return decoded_string;
 	#elif defined(MPT_CHARSET_ICONV)
 		iconv_t conv = iconv_t();
 		conv = iconv_open(Charset_wchar_t(), CharsetToString(charset));
@@ -1725,16 +1692,10 @@
 	{
 		return mpt::ustring();
 	}
-	#if MPT_CXX_AT_LEAST(17)
-		std::wstring decoded_string(required_size, wchar_t());
-		MultiByteToWideChar(codepage, 0, src.c_str(), -1, decoded_string.data(), required_size);
-		decoded_string.resize(decoded_string.size() - 1); // remove \0
-		return mpt::ToUnicode(decoded_string);
-	#else
-		std::vector<WCHAR> decoded_string(required_size);
-		MultiByteToWideChar(codepage, 0, src.c_str(), -1, decoded_string.data(), required_size);
-		return mpt::ToUnicode(std::wstring(decoded_string.data()));
-	#endif
+	std::wstring decoded_string(required_size, wchar_t());
+	MultiByteToWideChar(codepage, 0, src.c_str(), -1, decoded_string.data(), required_size);
+	decoded_string.resize(decoded_string.size() - 1); // remove \0
+	return mpt::ToUnicode(decoded_string);
 }
 
 #endif // MPT_OS_WINDOWS
Index: common/mptStringFormat.cpp
===================================================================
--- common/mptStringFormat.cpp	(revision 11987)
+++ common/mptStringFormat.cpp	(working copy)
@@ -10,7 +10,7 @@
 #include "stdafx.h"
 #include "mptStringFormat.h"
 
-#if MPT_CXX_AT_LEAST(17) && MPT_COMPILER_MSVC
+#if MPT_COMPILER_MSVC
 #define MPT_FORMAT_CXX17_INT 1
 #else
 #define MPT_FORMAT_CXX17_INT 0
Index: common/version.cpp
===================================================================
--- common/version.cpp	(revision 11987)
+++ common/version.cpp	(working copy)
@@ -323,9 +323,6 @@
 		#if defined(MPT_CHARSET_ICONV)
 			UL_(" +ICONV")
 		#endif
-		#if defined(MPT_CHARSET_CODECVTUTF8)
-			UL_(" +CODECVTUTF8")
-		#endif
 		#if defined(MPT_CHARSET_INTERNAL)
 			UL_(" +INTERNALCHARSETS")
 		#endif
Index: doc/backporting_patches.md
===================================================================
--- doc/backporting_patches.md	(revision 11987)
+++ doc/backporting_patches.md	(working copy)
@@ -10,7 +10,18 @@
 OpenMPT 1.28 / libopenmpt 0.4
 -----------------------------
 
+ *  Replace `std::abs` by `mpt::abs`.
+ *  Replace `std::byte` by `mpt::byte`.
+ *  Replace `std::clamp` by `mpt::clamp`.
+ *  Replace `std::data` by `mpt::data`.
+ *  Replace `std::gcd` by `mpt::gcd`.
+ *  Replace `std::lcm` by `mpt::lcm`.
  *  Replace `std::make_unique` by `mpt::make_unique`.
+ *  Replace `std::size` by `mpt::size`.
+ *  Replace `if constexpr` by `MPT_CONSTANT_IF`.
+ *  Replace `static_assert` by `MPT_STATIC_ASSERT`.
+ *  Replace `[[discard]]` by `MPT_DISCARD`.
+ *  Replace `[[fallthrough]]` by `MPT_FALLTHROUGH`.
 
 OpenMPT 1.27 / libopenmpt 0.3 
 -----------------------------
Index: libopenmpt/dox/changelog.md
===================================================================
--- libopenmpt/dox/changelog.md	(revision 11987)
+++ libopenmpt/dox/changelog.md	(working copy)
@@ -15,10 +15,11 @@
  *  [**Regression**] foo_openmpt: foo_openmpt is discontinued. Please use
     Kode54's fork foo_openmpt54:
     <https://www.foobar2000.org/components/view/foo_openmpt54>.
- *  [**Regression**] Support for C++11 has been removed. C++14 is now required.
+ *  [**Regression**] Support for C++11 and C++14 has been removed. C++17 is now
+    required.
  *  [**Regression**] Support for Visual Studio 2015 has been removed.
- *  [**Regression**] Support for GCC 4.8, 4.9 has been removed.
- *  [**Regression**] Support for Clang 3.6, 3.7 has been removed.
+ *  [**Regression**] Support for GCC 4.8, 4.9, 5, 6 has been removed.
+ *  [**Regression**] Support for Clang 3.6, 3.7, 3.8, 3.9, 4 has been removed.
 
 ### libopenmpt 0.4.0
 
Index: libopenmpt/dox/dependencies.md
===================================================================
--- libopenmpt/dox/dependencies.md	(revision 11987)
+++ libopenmpt/dox/dependencies.md	(working copy)
@@ -11,14 +11,14 @@
  *  Supported compilers for building libopenmpt:
      *  **Microsoft Visual Studio 2017** or higher, running on a x86-64 build
         system (other target systems are supported)
-     *  **GCC 5.1** or higher
-     *  **Clang 3.8** or higher
-     *  **MinGW-W64 5.1** or higher (it is recommended to preferably use
+     *  **GCC 7.1** or higher
+     *  **Clang 5** or higher
+     *  **MinGW-W64 7.1** or higher (it is recommended to preferably use
         posix threading model as opposed to win32 threading model, or at least
         have mingw-std-threads available otherwise)
      *  **emscripten 1.38.5** or higher
      *  **DJGPP GCC 7.2** or higher
-     *  any other **C++14 compliant** compiler (full standard compliant mode is
+     *  any other **C++17 compliant** compiler (full standard compliant mode is
         known to work with GCC >= 5.1 and Clang >= 3.8)
         
         libopenmpt makes the following assumptions about the C++ implementation
@@ -73,11 +73,11 @@
  *  Supported compilers for building openmpt123:
      *  **Microsoft Visual Studio 2017** or higher, running on a x86-64 build
         system (other target systems are supported)
-     *  **GCC 5.1** or higher
-     *  **Clang 3.8** or higher
-     *  **MinGW-W64 5.1** or higher
+     *  **GCC 7.1** or higher
+     *  **Clang 5** or higher
+     *  **MinGW-W64 7.1** or higher
      *  **DJGPP GCC 7.2** or higher
-     *  any **C++14 compliant** compiler
+     *  any **C++17 compliant** compiler
  *  Live sound output requires one of:
      *  **PulseAudio**
      *  **SDL 2**
Index: libopenmpt/dox/quickstart.md
===================================================================
--- libopenmpt/dox/quickstart.md	(revision 11987)
+++ libopenmpt/dox/quickstart.md	(working copy)
@@ -7,7 +7,7 @@
 
  1. Grab a `libopenmpt-VERSION.autotools.tar.gz` tarball.
  2. Get dependencies:
-     -  **gcc >= 5.1** or **clang >= 3.8**
+     -  **gcc >= 7.1** or **clang >= 5**
      -  **pkg-config >= 0.24**
      -  **zlib**
      -  **libogg**, **libvorbis**, **libvorbisfile**
Index: mptrack/ExceptionHandler.cpp
===================================================================
--- mptrack/ExceptionHandler.cpp	(revision 11987)
+++ mptrack/ExceptionHandler.cpp	(working copy)
@@ -50,17 +50,11 @@
 bool ExceptionHandler::useImplicitFallbackSEH = false;
 bool ExceptionHandler::useExplicitSEH = false;
 bool ExceptionHandler::handleStdTerminate = false;
-#if MPT_CXX_BEFORE(17)
-bool ExceptionHandler::handleStdUnexpected = false;
-#endif
 bool ExceptionHandler::handleMfcExceptions = false;
 
 
 static LPTOP_LEVEL_EXCEPTION_FILTER g_OriginalUnhandledExceptionFilter = nullptr;
 static std::terminate_handler g_OriginalTerminateHandler = nullptr;
-#if MPT_CXX_BEFORE(17)
-static std::unexpected_handler g_OriginalUnexpectedHandler = nullptr;
-#endif
 
 static UINT g_OriginalErrorMode = 0;
 
@@ -658,12 +652,6 @@
 	{
 		g_OriginalTerminateHandler = std::set_terminate(&mpt_terminate_handler);
 	}
-#if MPT_CXX_BEFORE(17)
-	if(handleStdUnexpected)
-	{
-		g_OriginalUnexpectedHandler = std::set_unexpected(&mpt_unexpected_handler);
-	}
-#endif
 }
 
 
@@ -699,13 +687,6 @@
 
 void ExceptionHandler::Unregister()
 {
-#if MPT_CXX_BEFORE(17)
-	if(handleStdUnexpected)
-	{
-		std::set_unexpected(g_OriginalUnexpectedHandler);
-		g_OriginalUnexpectedHandler = nullptr;
-	}
-#endif
 	if(handleStdTerminate)
 	{
 		std::set_terminate(g_OriginalTerminateHandler);
@@ -719,27 +700,6 @@
 }
 
 
-#if MPT_CXX_BEFORE(17)
-static void mpt_unexpected_handler()
-{
-	DebugReporter(DumpModeCrash, nullptr).ReportError(U_("An unexpected C++ exception occured: std::unexpected() called."));
-	// We disable the call to std::terminate() as that would re-renter the crash
-	// handler another time, but with less information available.
-#if 1
-	std::abort();
-#else
-	if(g_OriginalUnexpectedHandler)
-	{
-		g_OriginalUnexpectedHandler();
-	} else
-	{
-		std::terminate();
-	}
-#endif
-}
-#endif
-
-
 static void mpt_terminate_handler()
 {
 	DebugReporter(DumpModeCrash, nullptr).ReportError(U_("A C++ runtime crash occurred: std::terminate() called."));
Index: mptrack/Mptrack.cpp
===================================================================
--- mptrack/Mptrack.cpp	(revision 11987)
+++ mptrack/Mptrack.cpp	(working copy)
@@ -832,9 +832,6 @@
 		ExceptionHandler::useImplicitFallbackSEH = false;
 		ExceptionHandler::useExplicitSEH = true;
 		ExceptionHandler::handleStdTerminate = true;
-		#if MPT_CXX_BEFORE(17)
-			ExceptionHandler::handleStdUnexpected = true;
-		#endif
 		ExceptionHandler::handleMfcExceptions = true;
 		ExceptionHandler::debugExceptionHandler = true;
 	} else if(IsDebuggerPresent() || cmdInfo.m_noCrashHandler)
@@ -843,9 +840,6 @@
 		ExceptionHandler::useImplicitFallbackSEH = false;
 		ExceptionHandler::useExplicitSEH = false;
 		ExceptionHandler::handleStdTerminate = false;
-		#if MPT_CXX_BEFORE(17)
-			ExceptionHandler::handleStdUnexpected = false;
-		#endif
 		ExceptionHandler::handleMfcExceptions = false;
 		ExceptionHandler::debugExceptionHandler = false;
 	} else
@@ -854,9 +848,6 @@
 		ExceptionHandler::useImplicitFallbackSEH = true;
 		ExceptionHandler::useExplicitSEH = true;
 		ExceptionHandler::handleStdTerminate = true;
-		#if MPT_CXX_BEFORE(17)
-			ExceptionHandler::handleStdUnexpected = true;
-		#endif
 		ExceptionHandler::handleMfcExceptions = true;
 		ExceptionHandler::debugExceptionHandler = false;
 	}
Index: mptrack/Settings.cpp
===================================================================
--- mptrack/Settings.cpp	(revision 11987)
+++ mptrack/Settings.cpp	(working copy)
@@ -62,9 +62,6 @@
 }
 
 
-#if MPT_CXX_AT_LEAST(17)
-
-
 mpt::ustring SettingValue::FormatValueAsString() const
 {
 	switch(GetType())
@@ -118,65 +115,6 @@
 }
 
 
-#else
-
-
-mpt::ustring SettingValue::FormatValueAsString() const
-{
-	switch(GetType())
-	{
-		case SettingTypeBool:
-			return mpt::ufmt::val(valueBool);
-			break;
-		case SettingTypeInt:
-			return mpt::ufmt::val(valueInt);
-			break;
-		case SettingTypeFloat:
-			return mpt::ufmt::val(valueFloat);
-			break;
-		case SettingTypeString:
-			return valueString;
-			break;
-		case SettingTypeBinary:
-			return Util::BinToHex(mpt::as_span(valueBinary));
-			break;
-		case SettingTypeNone:
-		default:
-			return mpt::ustring();
-			break;
-	}
-}
-
-
-void SettingValue::SetFromString(const AnyStringLocale &newVal)
-{
-	switch(GetType())
-	{
-		case SettingTypeBool:
-			valueBool = ConvertStrTo<bool>(newVal);
-			break;
-		case SettingTypeInt:
-			valueInt = ConvertStrTo<int32>(newVal);
-			break;
-		case SettingTypeFloat:
-			valueFloat = ConvertStrTo<double>(newVal);
-			break;
-		case SettingTypeString:
-			valueString = newVal;
-			break;
-		case SettingTypeBinary:
-			valueBinary = Util::HexToBin(newVal);
-			break;
-		case SettingTypeNone:
-		default:
-			break;
-	}
-}
-
-
-#endif
-
-
 SettingValue SettingsContainer::BackendsReadSetting(const SettingPath &path, const SettingValue &def) const
 {
 	return backend->ReadSetting(path, def);
Index: mptrack/Settings.h
===================================================================
--- mptrack/Settings.h	(revision 11987)
+++ mptrack/Settings.h	(working copy)
@@ -19,9 +19,7 @@
 
 #include <map>
 #include <set>
-#if MPT_CXX_AT_LEAST(17)
 #include <variant>
-#endif
 
 
 OPENMPT_NAMESPACE_BEGIN
@@ -40,7 +38,6 @@
 // SettingValue is a variant type that stores any type that can natively be represented in a config backend.
 // Any other type that should be stored must provide a matching ToSettingValue and FromSettingValue.
 // Other types can optionally also set a type tag which would get checked in debug builds.
-#if MPT_CXX_AT_LEAST(17)
 class SettingValue
 {
 private:
@@ -190,185 +187,6 @@
 	mpt::ustring FormatValueAsString() const;
 	void SetFromString(const AnyStringLocale &newVal);
 };
-#else
-class SettingValue
-{
-private:
-	bool valueBool;
-	int32 valueInt;
-	double valueFloat;
-	mpt::ustring valueString;
-	std::vector<mpt::byte> valueBinary;
-	SettingType type;
-	std::string typeTag;
-	void Init()
-	{
-		valueBool = false;
-		valueInt = 0;
-		valueFloat = 0.0;
-		valueString = mpt::ustring();
-		valueBinary.clear();
-		type = SettingTypeNone;
-		typeTag = std::string();
-	}
-public:
-	bool operator == (const SettingValue &other) const
-	{
-		return type == other.type
-			&& typeTag == other.typeTag
-			&& valueBool == other.valueBool
-			&& valueInt == other.valueInt
-			&& valueFloat == other.valueFloat
-			&& valueString == other.valueString
-			&& valueBinary == other.valueBinary
-			;
-	}
-	bool operator != (const SettingValue &other) const
-	{
-		return !(*this == other);
-	}
-	SettingValue()
-	{
-		Init();
-	}
-	SettingValue(const SettingValue &other)
-	{
-		Init();
-		*this = other;
-	}
-	SettingValue & operator = (const SettingValue &other)
-	{
-		if(this == &other)
-		{
-			return *this;
-		}
-		MPT_ASSERT(type == SettingTypeNone || (type == other.type && typeTag == other.typeTag));
-		type = other.type;
-		valueBool = other.valueBool;
-		valueInt = other.valueInt;
-		valueFloat = other.valueFloat;
-		valueString = other.valueString;
-		valueBinary = other.valueBinary;
-		typeTag = other.typeTag;
-		return *this;
-	}
-	SettingValue(bool val)
-	{
-		Init();
-		type = SettingTypeBool;
-		valueBool = val;
-	}
-	SettingValue(int32 val)
-	{
-		Init();
-		type = SettingTypeInt;
-		valueInt = val;
-	}
-	SettingValue(double val)
-	{
-		Init();
-		type = SettingTypeFloat;
-		valueFloat = val;
-	}
-	SettingValue(const mpt::ustring &val)
-	{
-		Init();
-		type = SettingTypeString;
-		valueString = val;
-	}
-	SettingValue(const std::vector<mpt::byte> &val)
-	{
-		Init();
-		type = SettingTypeBinary;
-		valueBinary =  val;
-	}
-	SettingValue(bool val, const std::string &typeTag_)
-	{
-		Init();
-		type = SettingTypeBool;
-		typeTag = typeTag_;
-		valueBool = val;
-	}
-	SettingValue(int32 val, const std::string &typeTag_)
-	{
-		Init();
-		type = SettingTypeInt;
-		typeTag = typeTag_;
-		valueInt = val;
-	}
-	SettingValue(double val, const std::string &typeTag_)
-	{
-		Init();
-		type = SettingTypeFloat;
-		typeTag = typeTag_;
-		valueFloat = val;
-	}
-	SettingValue(const mpt::ustring &val, const std::string &typeTag_)
-	{
-		Init();
-		type = SettingTypeString;
-		typeTag = typeTag_;
-		valueString = val;
-	}
-	SettingValue(const std::vector<mpt::byte> &val, const std::string &typeTag_)
-	{
-		Init();
-		type = SettingTypeBinary;
-		typeTag = typeTag_;
-		valueBinary =  val;
-	}
-	// these need to be explicitly deleted because otherwise the bool overload will catch the pointers
-	SettingValue(const char *val) = delete;
-	SettingValue(const wchar_t *val) = delete;
-	SettingValue(const char *val, const std::string &typeTag_) = delete;
-	SettingValue(const wchar_t *val, const std::string &typeTag_) = delete;
-	SettingType GetType() const
-	{
-		return type;
-	}
-	bool HasTypeTag() const
-	{
-		return !typeTag.empty();
-	}
-	std::string GetTypeTag() const
-	{
-		return typeTag;
-	}
-	template <typename T>
-	T as() const
-	{
-		return *this;
-	}
-	operator bool () const
-	{
-		MPT_ASSERT(type == SettingTypeBool);
-		return valueBool;
-	}
-	operator int32 () const
-	{
-		MPT_ASSERT(type == SettingTypeInt);
-		return valueInt;
-	}
-	operator double () const
-	{
-		MPT_ASSERT(type == SettingTypeFloat);
-		return valueFloat;
-	}
-	operator mpt::ustring () const
-	{
-		MPT_ASSERT(type == SettingTypeString);
-		return valueString;
-	}
-	operator std::vector<mpt::byte> () const
-	{
-		MPT_ASSERT(type == SettingTypeBinary);
-		return valueBinary;
-	}
-	mpt::ustring FormatTypeAsString() const;
-	mpt::ustring FormatValueAsString() const;
-	void SetFromString(const AnyStringLocale &newVal);
-};
-#endif
 
 
 template<typename T>
Index: README.md
===================================================================
--- README.md	(revision 11987)
+++ README.md	(working copy)
@@ -172,9 +172,9 @@
 
         The minimum required compiler versions are:
 
-         -  gcc 5
+         -  gcc 7
 
-         -  clang 3.8
+         -  clang 5
 
         The Makefile requires pkg-config for native builds.
         For sound output in openmpt123, PortAudio or SDL is required.
Index: soundlib/Load_mdl.cpp
===================================================================
--- soundlib/Load_mdl.cpp	(revision 11987)
+++ soundlib/Load_mdl.cpp	(working copy)
@@ -598,14 +598,7 @@
 				if(sampleHeader.smpNum == 0)
 					continue;
 				#if 1
-					#if MPT_GCC_BEFORE(6,1,0)
-					#pragma GCC diagnostic push
-					#pragma GCC diagnostic ignored "-Wtype-limits"
-					#endif
 					STATIC_ASSERT((mpt::limits<decltype(sampleHeader.smpNum)>::max)() < MAX_SAMPLES);
-					#if MPT_GCC_BEFORE(6,1,0)
-					#pragma GCC diagnostic pop
-					#endif
 				#else
 					MPT_MAYBE_CONSTANT_IF(sampleHeader.smpNum >= MAX_SAMPLES)
 						continue;