https://gcc.gnu.org/bugzilla/show_bug.cgi?id=68683
--- Comment #1 from Jason Merrill <jason at gcc dot gnu.org> --- Author: jason Date: Mon Dec 7 21:45:13 2015 New Revision: 231385 URL: https://gcc.gnu.org/viewcvs?rev=231385&root=gcc&view=rev Log: PR c++/68683 * constraint.cc (satisfy_argument_deduction_constraint): Set TYPE_CANONICAL to NULL_TREE if PLACEHOLDER_TYPE_CONSTRAINTS are changed. Added: trunk/gcc/testsuite/g++.dg/concepts/pr68683.C Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/constraint.cc