facebook / folly

Hello!

I am very confused by the change introduced in 2cf8c88. According to https://en.cppreference.com/w/cpp/feature_test, #if defined(__cpp_lib_ranges) was a correct way to check if std::ranges is usable. I believe that #if __has_include(<ranges>) is not working as expected, since ranges.h is available in libfmt - a folly dependency. This code won't compile in C++17. And also it is not even done correctly in some places ("range" vs "ranges"):

folly/folly/test/PortabilityTest.cpp

Lines 58 to 60 in 2cf8c88

    
           #if __has_include(<range>) 
        
           static_assert(std::ranges::random_access_range<std::vector<int>>); 
        
           #endif

	#if __has_include(<range>)
	static_assert(std::ranges::random_access_range<std::vector<int>>);
	#endif

Broken check for std::ranges?