We need to include <iostream>, otherwise it complains:
cpp-ethereum/evmjit/libevmjit/ExecutionEngine.cpp:147:2:
error: implicit instantiation of undefined template
'std::__1::basic_ostream<char, std::__1::char_traits<char> >'
clog(JIT) << " + " << std::chrono::duration_cast<std::chrono::milliseconds>(executionEndTime - executionStartTime).cou...
^
cpp-ethereum/evmjit/libevmjit/Utils.h:15:23: note:
expanded from macro 'clog' #define clog(CHANNEL) std::ostream(nullptr)
^
/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/../include/c++/v1/iosfwd:111:33: note:
template is declared here
class _LIBCPP_TYPE_VIS_ONLY basic_ostream;
^
Lu Guanqun
Paweł Bylica