In file included from /home/dtscode/Desktop/SLang/src/lexer.cpp:9:0:
/home/dtscode/Desktop/SLang/include/util.hpp:5:43: error: ‘void utility::forEachDigit(T, T, U) [with T = std::istream_iterator<char>; U = getToken(std::istream*)::__lambda0]’, declared using local type ‘getToken(std::istream*)::__lambda0’, is used but never defined [-fpermissive]
     template<typename T, typename U> void forEachDigit(T, T, U);
                                           ^
make[2]: *** [CMakeFiles/build/slang.dir/src/lexer.cpp.o] Error 1
make[1]: *** [CMakeFiles/build/slang.dir/all] Error 2
make: *** [all] Error 2