option_test fails with g++ 7 -std=c++1z
herumi opened this issue · comments
Please compile with -fno-new-ttp-matching .
I'll fix it later.
The resolution of DR 150 on matching of template template parameters, allowing default template arguments to make a template match a parameter, is currently enabled by default in C++17 mode only. The default can be overridden with -f{no-,}new-ttp-matching.