https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69302
--- Comment #8 from Jonathan Wakely <redi at gcc dot gnu.org> --- Fixed by r253266 PR c++/56973, DR 696 - capture constant variables only as needed. * expr.c (mark_use): Split out from mark_rvalue_use and mark_lvalue_use. Handle lambda capture of constant variables. (mark_lvalue_use_nonread): New. * semantics.c (process_outer_var_ref): Don't capture a constant variable until forced. * pt.c (processing_nonlambda_template): New. * call.c (build_this): Check it. * decl2.c (grok_array_decl): Call mark_rvalue_use and mark_lvalue_use_nonread. * init.c (constant_value_1): Don't call mark_rvalue_use. * typeck.c (build_static_cast): Handle lambda capture.
