Problems when building on GCC 5.5.0 (Ubuntu 16.04)

[saveman]

Following errors are present (maybe more):
/octargs/include/octargs/internal/../internal/../dictionary.hpp:316:26: error: ‘init_mode’ is not a class, namespace, or enumeration
/octargs/include/octargs/internal/parser_data.hpp:55:78: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:64:82: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:74:79: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:79:82: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:69:79: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:185:57: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
make[2]: Target 'examples/calc/CMakeFiles/octargs_calc.dir/build' not remade because of errors.
/octargs/include/octargs/internal/../internal/../dictionary.hpp:316:26: error: ‘init_mode’ is not a class, namespace, or enumeration
/octargs/include/octargs/internal/parser_data.hpp:64:82: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::cat_app_settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:69:79: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::cat_app_settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:79:82: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::cat_app_settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:185:57: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::cat_app_settings>’ has no member named ‘weak_from_this’
make[2]: Target 'examples/cat/CMakeFiles/octargs_cat.dir/build' not remade because of errors.
/octargs/include/octargs/internal/../internal/../dictionary.hpp:316:26: error: ‘init_mode’ is not a class, namespace, or enumeration
/octargs/include/octargs/internal/parser_data.hpp:84:82: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::app_settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:64:82: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::app_settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:69:79: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::app_settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:74:79: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::app_settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:185:57: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::app_settings>’ has no member named ‘weak_from_this’
make[2]: Target 'examples/getfile/CMakeFiles/octargs_getfile.dir/build' not remade because of errors.
/octargs/include/octargs/internal/../internal/../dictionary.hpp:316:26: error: ‘init_mode’ is not a class, namespace, or enumeration
/octargs/include/octargs/internal/parser_data.hpp:64:82: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:74:79: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:69:79: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:79:82: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:185:57: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
make[2]: Target 'examples/head/CMakeFiles/octargs_head.dir/build' not remade because of errors.
/octargs/include/octargs/internal/../internal/../dictionary.hpp:316:26: error: ‘init_mode’ is not a class, namespace, or enumeration
/octargs/include/octargs/internal/parser_data.hpp:55:78: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:185:57: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:64:82: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:74:79: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:79:82: error: ‘class oct::args::internal::basic_parser_data<char, void>’ has no member named ‘weak_from_this’
make[2]: Target 'examples/sum/CMakeFiles/octargs_sum.dir/build' not remade because of errors.
/octargs/include/octargs/internal/../internal/../dictionary.hpp:316:26: error: ‘init_mode’ is not a class, namespace, or enumeration
/octargs/include/octargs/internal/parser_data.hpp:185:57: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:64:82: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:74:79: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:69:79: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::settings>’ has no member named ‘weak_from_this’
/octargs/include/octargs/internal/parser_data.hpp:79:82: error: ‘class oct::args::internal::basic_parser_data<char, oct_args_examples::settings>’ has no member named ‘weak_from_this’
make[2]: Target 'examples/win_head/CMakeFiles/octargs_win_head.dir/build' not remade because of errors.