Having upgraded to XCode 10.2, I'm suddenly getting the following error:
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/iterator:1665:16: note:
non-constexpr function 'begin' cannot be used in a constant expression
return __c.begin();
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/array:270:14: note:
declared here
iterator begin() _NOEXCEPT {return iterator(data());}
It looks like some constexprs have disappeared from the header.
Reverting back to 10.1 fixes the problem.
