Proper way to check endianness?

Is this the correct was to test for endianness? I’m running Ubuntu on a Surface Pro 3, which is little endian, however VSTGUI reports that it’s big endian.

 if constexpr(ByteOrder::kNativeByteOrder == ByteOrder::kLittleEndianByteOrder) {
   // System using litttle endian
 }

else {
  // System using big endian
}
rjonkman@rjonkman-Surface-Pro-3:~/coding/VST_3.7.5/build$ lscpu
Architecture:                    x86_64
CPU op-mode(s):                  32-bit, 64-bit
Byte Order:                      Little Endian

Looks like the endian check in VSTGUI does not work for the compiler you use. See vstgui/vstguibase.h at develop · steinbergmedia/vstgui · GitHub
Most compilers will define __LITTLE_ENDIAN__. What does your compiler define for the endian order?

For my compiler, GNU 9.4, the define is __LITTLE_ENDIAN. Looks there are many possible defines.
https://sourceforge.net/p/predef/wiki/Endianness/

Ok, I will add this to VSTGUI.