Use std::enable_if_t consistently, resolves #734

Author: mikke89

Include/RmlUi/Core/DataTypeRegister.h

@@ -74,7 +74,7 @@ class RMLUICORE_API DataTypeRegister final : NonCopyMoveable {
 private:
 	// Get definition for scalar types that can be assigned to and from Rml::Variant.
 	// We automatically register these when needed, so users don't have to register trivial types manually.
-	template <typename T, typename std::enable_if<!PointerTraits<T>::is_pointer::value && is_builtin_data_scalar<T>::value, int>::type = 0>
+	template <typename T, typename std::enable_if_t<!PointerTraits<T>::is_pointer::value && is_builtin_data_scalar<T>::value, int> = 0>
 	VariableDefinition* GetDefinitionDetail()
 	{
 		static_assert(!std::is_const<T>::value, "Data binding variables cannot point to constant variables.");
@@ -92,7 +92,7 @@ class RMLUICORE_API DataTypeRegister final : NonCopyMoveable {
 
 	// Get definition for types that are not a built-in scalar.
 	// These must already have been registered by the user.
-	template <typename T, typename std::enable_if<!PointerTraits<T>::is_pointer::value && !is_builtin_data_scalar<T>::value, int>::type = 0>
+	template <typename T, typename std::enable_if_t<!PointerTraits<T>::is_pointer::value && !is_builtin_data_scalar<T>::value, int> = 0>
 	VariableDefinition* GetDefinitionDetail()
 	{
 		FamilyId id = Family<T>::Id();
@@ -110,7 +110,7 @@ class RMLUICORE_API DataTypeRegister final : NonCopyMoveable {
 
 	// Get definition for pointer types, or create one as needed.
 	// This will create a wrapper definition that forwards the call to the definition of the underlying type.
-	template <typename T, typename std::enable_if<PointerTraits<T>::is_pointer::value, int>::type = 0>
+	template <typename T, typename std::enable_if_t<PointerTraits<T>::is_pointer::value, int> = 0>
 	VariableDefinition* GetDefinitionDetail()
 	{
 		static_assert(PointerTraits<T>::is_pointer::value, "Invalid pointer type provided.");

Include/RmlUi/Core/DataVariable.h

@@ -261,13 +261,13 @@ class MemberScalarGetSetFuncDefinition final : public VariableDefinition {
 	bool Set(void* ptr, const Variant& variant) override { return SetDetail(ptr, variant); }
 
 private:
-	template <typename T = MemberGetType, typename std::enable_if<IsVoidMemberFunc<T>::value, int>::type = 0>
+	template <typename T = MemberGetType, typename std::enable_if_t<IsVoidMemberFunc<T>::value, int> = 0>
 	bool GetDetail(void* /*ptr*/, Variant& /*variant*/)
 	{
 		return false;
 	}
 
-	template <typename T = MemberGetType, typename std::enable_if<!IsVoidMemberFunc<T>::value, int>::type = 0>
+	template <typename T = MemberGetType, typename std::enable_if_t<!IsVoidMemberFunc<T>::value, int> = 0>
 	bool GetDetail(void* ptr, Variant& variant)
 	{
 		RMLUI_ASSERT(member_get_func_ptr);
@@ -277,13 +277,13 @@ class MemberScalarGetSetFuncDefinition final : public VariableDefinition {
 		return result;
 	}
 
-	template <typename T = MemberSetType, typename std::enable_if<IsVoidMemberFunc<T>::value, int>::type = 0>
+	template <typename T = MemberSetType, typename std::enable_if_t<IsVoidMemberFunc<T>::value, int> = 0>
 	bool SetDetail(void* /*ptr*/, const Variant& /*variant*/)
 	{
 		return false;
 	}
 
-	template <typename T = MemberSetType, typename std::enable_if<!IsVoidMemberFunc<T>::value, int>::type = 0>
+	template <typename T = MemberSetType, typename std::enable_if_t<!IsVoidMemberFunc<T>::value, int> = 0>
 	bool SetDetail(void* ptr, const Variant& variant)
 	{
 		RMLUI_ASSERT(member_set_func_ptr);

Include/RmlUi/Core/Property.h

@@ -60,7 +60,7 @@ class RMLUICORE_API Property {
 		definition = nullptr;
 		parser_index = -1;
 	}
-	template <typename EnumType, typename = typename std::enable_if<std::is_enum<EnumType>::value, EnumType>::type>
+	template <typename EnumType, typename = typename std::enable_if_t<std::is_enum<EnumType>::value, EnumType>>
 	Property(EnumType value) : value(static_cast<int>(value)), unit(Unit::KEYWORD), specificity(-1)
 	{}
 

Include/RmlUi/Core/Variant.inl

@@ -47,7 +47,7 @@ Variant& Variant::operator=(T&& t)
 	return *this;
 }
 
-template <typename T, typename std::enable_if<!std::is_enum<T>::value, int>::type>
+template <typename T, typename std::enable_if_t<!std::is_enum<T>::value, int>>
 bool Variant::GetInto(T& value) const
 {
 	switch (type)
@@ -83,7 +83,7 @@ bool Variant::GetInto(T& value) const
 	return false;
 }
 
-template <typename T, typename std::enable_if<std::is_enum<T>::value, int>::type>
+template <typename T, typename std::enable_if_t<std::is_enum<T>::value, int>>
 bool Variant::GetInto(T& value) const
 {
 	static_assert(sizeof(T) <= sizeof(int64_t), "Enum underlying type exceeds maximum supported integer type size");