Gcc is quite liberal when it comes to constexpr. For example, it allows to use math and string comparisons in constexpr context. However, clang does not. Ie
./core/cmd_line_parser/command_line.hpp:223:12: note: non-constexpr function 'strncmp' cannot be used in a constant expression
return strncmp(a.name, b.name, m_str_maxlen) < 0;
Is there an option to enable such extensions, or any reliable work-around. Note: while strcmp and strncmp should be trivial to implement, math functions are not, so I guess they have to produce dummy values in that case.
