@jdoerrie who implemented base::size

I'm assuming you are talking about C arrays, as it's working fine for empty std::arrays. Here the compilation failure is actually working as intended, as zero-length arrays are not allowed by the standard [1]:

"""
[...] If the constant-expression is present, it shall be a converted constant expression of type std​::​size_­t and its value shall be greater than zero. [...]
"""

A small reproduction case is here: https://godbolt.org/g/wTsb7R. Because of this, I am marking this as WontFix. Would it be possible for you to use an empty std::array to work around this?


[1] http://eel.is/c++draft/dcl.array#1