https://gcc.gnu.org/bugzilla/show_bug.cgi?id=82085
--- Comment #8 from Roland B <rbock at eudoxos dot de> --- (In reply to Paolo Carlini from comment #7) > Fixed trunk and 7.3.0 so far. Awesome! Sadly, my "real" code still produces an internal compile error. I will try to create a new minimal example. Until then, you can observe the code here: https://github.com/rbock/sqlpp17/tree/1c424f9c1e4d9d9fa7e1c0cb48d27aec190f0da7 And then something like: export SOURCE_ROOT=$HOME/projects/sqlpp17 /usr/local/gcc-trunk/bin/g++ -I$SOURCE_ROOT/include -I$SOURCE_ROOT/tests -std=c++1z -Wall -Wpedantic $SOURCE_ROOT/tests/serialize/join.cpp This creates: sqlpp17/char_sequence.h:70:80: internal compiler error: unexpected expression āNā of kind template_parm_index using make_char_sequence_t = typename make_char_sequence<StringLiteral>::type; ^ 0x6bd33a cxx_eval_constant_expression ../../gcc-trunk/gcc/cp/constexpr.c:4638 ...