Can't compile tongrams

[pedro-alonsod]

Hi I get an error when trying to compile the code:

In file included from /SSD/pedros-corner/tongrams/include/utils/util.hpp:19:0, from /SSD/pedros-corner/tongrams/test/test_count_model.cpp:3: /SSD/pedros-corner/tongrams/include/../external/essentials/include/essentials.hpp: In member function ‘typename std::enable_if<std::is_pod<_Tp>::value>::type essentials::sizer::visit(T&)’: /SSD/pedros-corner/tongrams/include/../external/essentials/include/essentials.hpp:361:62: error: must #include <typeinfo> before using typeid node n(pod_bytes(val), m_current->depth + 1, typeid(T).name()); ^ /SSD/pedros-corner/tongrams/include/../external/essentials/include/essentials.hpp: In member function ‘typename std::enable_if<std::is_pod<_Tp>::value>::type essentials::sizer::visit(std::vector<_RealType>&)’: /SSD/pedros-corner/tongrams/include/../external/essentials/include/essentials.hpp:374:37: error: must #include <typeinfo> before using typeid typeid(std::vector<T>).name()); ^ /SSD/pedros-corner/tongrams/include/../external/essentials/include/essentials.hpp: In member function ‘typename std::enable_if<(! std::is_pod<_Tp>::value)>::type essentials::sizer::visit(std::vector<_RealType>&)’: /SSD/pedros-corner/tongrams/include/../external/essentials/include/essentials.hpp:385:50: error: must #include <typeinfo> before using typeid node n(0, parent->depth + 1, typeid(T).name()); ^ /SSD/pedros-corner/tongrams/include/../external/essentials/include/essentials.hpp: In function ‘void essentials::print_size(Data&)’: /SSD/pedros-corner/tongrams/include/../external/essentials/include/essentials.hpp:437:30: error: must #include <typeinfo> before using typeid sizer visitor(typeid(Data).name()); ^ In file included from /SSD/pedros-corner/tongrams/test/test_count_model.cpp:6:0: /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp: At global scope: /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:13:45: error: ‘empty’ declared as an ‘inline’ field inline static const std::string empty = ""; ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:13:45: error: in-class initialization of static data member ‘const string cmd_line_parser::parser::empty’ of non-literal type /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:13:45: error: call to non-constexpr function ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp: In member function ‘T cmd_line_parser::parser::parse(const string&) const’: /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:115:12: error: expected ‘(’ before ‘constexpr’ if constexpr (std::is_same<T, std::string>::value) { ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:117:11: error: ‘else’ without a previous ‘if’ } else if constexpr (std::is_same<T, char>::value or std::is_same<T, signed char>::value or ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:117:19: error: expected ‘(’ before ‘constexpr’ } else if constexpr (std::is_same<T, char>::value or std::is_same<T, signed char>::value or ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:120:11: error: ‘else’ without a previous ‘if’ } else if constexpr (std::is_same<T, unsigned int>::value or std::is_same<T, int>::value or ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:120:19: error: expected ‘(’ before ‘constexpr’ } else if constexpr (std::is_same<T, unsigned int>::value or std::is_same<T, int>::value or ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:124:11: error: ‘else’ without a previous ‘if’ } else if constexpr (std::is_same<T, unsigned long int>::value or ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:124:19: error: expected ‘(’ before ‘constexpr’ } else if constexpr (std::is_same<T, unsigned long int>::value or ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:129:11: error: ‘else’ without a previous ‘if’ } else if constexpr (std::is_same<T, float>::value or std::is_same<T, double>::value or ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:129:19: error: expected ‘(’ before ‘constexpr’ } else if constexpr (std::is_same<T, float>::value or std::is_same<T, double>::value or ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:132:11: error: ‘else’ without a previous ‘if’ } else if constexpr (std::is_same<T, bool>::value) { ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:132:19: error: expected ‘(’ before ‘constexpr’ } else if constexpr (std::is_same<T, bool>::value) { ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:144:5: error: expected ‘}’ at end of input } ^ /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = std::__cxx11::basic_string<char>; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:104:24: required from ‘T cmd_line_parser::parser::get(const string&) const [with T = std::__cxx11::basic_string<char>; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /SSD/pedros-corner/tongrams/test/test_count_model.cpp:40:69: required from here /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] /SSD/pedros-corner/tongrams/test/../external/cmd_line_parser/include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ CMakeFiles/test_count_model.dir/build.make:62: recipe for target 'CMakeFiles/test_count_model.dir/test/test_count_model.cpp.o' failed make[2]: *** [CMakeFiles/test_count_model.dir/test/test_count_model.cpp.o] Error 1 CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/test_count_model.dir/all' failed make[1]: *** [CMakeFiles/test_count_model.dir/all] Error 2 Makefile:83: recipe for target 'all' failed make: *** [all] Error 2

I'm not sure why this is happening. Is on Ubuntu 16.04, a server. Any ideas?. Thanks.

[jermp]

Hi, it seems a problem relative to the external library
https://github.com/jermp/cmd_line_parser
which requires C++17 for "if constexpr".
Are you compiling with C++17 ?
Can you try to compile the cmd_line_parser standalone?

[pedro-alonsod]

No, also not:
(base) pedalo@B4375:~/Documents/GithubCode/cmd_line_parser/src/build$ cmake .. -- The C compiler identification is GNU 5.4.0 -- The CXX compiler identification is GNU 5.4.0 -- Check for working C compiler: /usr/bin/cc -- Check for working C compiler: /usr/bin/cc -- works -- Detecting C compiler ABI info -- Detecting C compiler ABI info - done -- Detecting C compile features -- Detecting C compile features - done -- Check for working CXX compiler: /usr/bin/c++ -- Check for working CXX compiler: /usr/bin/c++ -- works -- Detecting CXX compiler ABI info -- Detecting CXX compiler ABI info - done -- Detecting CXX compile features -- Detecting CXX compile features - done -- CMAKE_BUILD_TYPE: Release -- Configuring done -- Generating done -- Build files have been written to: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/build (base) pedalo@B4375:~/Documents/GithubCode/cmd_line_parser/src/build$ make Scanning dependencies of target test_parse [ 25%] Building CXX object CMakeFiles/test_parse.dir/test_parse.cpp.o In file included from /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:4:0: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:13:45: error: ‘empty’ declared as an ‘inline’ field inline static const std::string empty = ""; ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:13:45: error: in-class initialization of static data member ‘const string cmd_line_parser::parser::empty’ of non-literal type /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:13:45: error: call to non-constexpr function ‘std::__cxx11::basic_string<_CharT, _Traits, _Alloc>::basic_string(const _CharT*, const _Alloc&) [with _CharT = char; _Traits = std::char_traits<char>; _Alloc = std::allocator<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In member function ‘T cmd_line_parser::parser::parse(const string&) const’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:115:12: error: expected ‘(’ before ‘constexpr’ if constexpr (std::is_same<T, std::string>::value) { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:117:11: error: ‘else’ without a previous ‘if’ } else if constexpr (std::is_same<T, char>::value or std::is_ ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:117:19: error: expected ‘(’ before ‘constexpr’ } else if constexpr (std::is_same<T, char>::value or std::is_ ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:120:11: error: ‘else’ without a previous ‘if’ } else if constexpr (std::is_same<T, unsigned int>::value or ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:120:19: error: expected ‘(’ before ‘constexpr’ } else if constexpr (std::is_same<T, unsigned int>::value or ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:124:11: error: ‘else’ without a previous ‘if’ } else if constexpr (std::is_same<T, unsigned long int>::valu ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:124:19: error: expected ‘(’ before ‘constexpr’ } else if constexpr (std::is_same<T, unsigned long int>::valu ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:129:11: error: ‘else’ without a previous ‘if’ } else if constexpr (std::is_same<T, float>::value or std::is ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:129:19: error: expected ‘(’ before ‘constexpr’ } else if constexpr (std::is_same<T, float>::value or std::is ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:132:11: error: ‘else’ without a previous ‘if’ } else if constexpr (std::is_same<T, bool>::value) { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:132:19: error: expected ‘(’ before ‘constexpr’ } else if constexpr (std::is_same<T, bool>::value) { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: error: expected ‘}’ at end of input } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = char; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = char; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:27:27: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = signed char; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = signed char; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:28:34: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = unsigned char; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = unsigned char; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:29:36: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = short int; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = short int; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:31:36: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = int; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = int; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:32:31: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = long int; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = long int; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:33:38: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = short unsigned int; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = short unsigned int; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:35:44: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = unsigned int; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = unsigned int; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:36:38: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = long unsigned int; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = long unsigned int; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:37:50: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = float; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = float; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:39:32: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = double; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = double; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:40:32: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = long double; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = long double; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:41:41: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp: In instantiation of ‘T cmd_line_parser::parser::parse(const string&) const [with T = bool; std::__cxx11::string = std::__cxx11::basic_string<char>]’: /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:21:9: required from ‘void test(const cmd_line_parser::parser&, const string&) [with T = bool; std::__cxx11::string = std::__cxx11::basic_string<char>]’ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/test_parse.cpp:43:30: required from here /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:144:5: warning: no return statement in function returning non-void [-Wreturn-type] } ^ /nfs/staff/pedalo/Documents/GithubCode/cmd_line_parser/src/../include/parser.hpp:114:32: warning: unused parameter ‘value’ [-Wunused-parameter] T parse(std::string const& value) const { ^ CMakeFiles/test_parse.dir/build.make:62: recipe for target 'CMakeFiles/test_parse.dir/test_parse.cpp.o' failed make[2]: *** [CMakeFiles/test_parse.dir/test_parse.cpp.o] Error 1 CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/test_parse.dir/all' failed make[1]: *** [CMakeFiles/test_parse.dir/all] Error 2 Makefile:83: recipe for target 'all' failed make: *** [all] Error 2
So I need to update the GNU or any other suggestion?

[jermp]

Yes, probably you should.
I tried myself with gcc4.9 and got this:
g++-4.9: error: unrecognized command line option ‘-std=c++17’
as I expected.
Try to use gcc 7 at least. Thanks and let me know.