Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk and perhaps 13?
-- >8 -- invalid_tparm_referent_p was rejecting using the address of a class NTTP object as a template argument, but this should be fine. PR c++/113242 gcc/cp/ChangeLog: * pt.cc (invalid_tparm_referent_p) <case ADDR_EXPR>: Suppress DECL_ARTIFICIAL rejection test for class NTTP objects. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/nontype-class61.C: New test. --- gcc/cp/pt.cc | 3 ++- gcc/testsuite/g++.dg/cpp2a/nontype-class61.C | 27 ++++++++++++++++++++ 2 files changed, 29 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/nontype-class61.C diff --git a/gcc/cp/pt.cc b/gcc/cp/pt.cc index 154ac76cb65..8c7d178328d 100644 --- a/gcc/cp/pt.cc +++ b/gcc/cp/pt.cc @@ -7219,7 +7219,8 @@ invalid_tparm_referent_p (tree type, tree expr, tsubst_flags_t complain) * a string literal (5.13.5), * the result of a typeid expression (8.2.8), or * a predefined __func__ variable (11.4.1). */ - else if (VAR_P (decl) && DECL_ARTIFICIAL (decl)) + else if (VAR_P (decl) && !DECL_NTTP_OBJECT_P (decl) + && DECL_ARTIFICIAL (decl)) { if (complain & tf_error) error ("the address of %qD is not a valid template argument", diff --git a/gcc/testsuite/g++.dg/cpp2a/nontype-class61.C b/gcc/testsuite/g++.dg/cpp2a/nontype-class61.C new file mode 100644 index 00000000000..90805a05ecf --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/nontype-class61.C @@ -0,0 +1,27 @@ +// PR c++/113242 +// { dg-do compile { target c++20 } } + +struct wrapper { + int n; +}; + +template<const wrapper& X> +void f1() { + static_assert(X.n == 42); +} + +template<const wrapper* X> +void f2() { + static_assert(X->n == 42); +} + +template<wrapper X> +void g() { + f1<X>(); + f2<&X>(); +} + +int main() { + constexpr wrapper X = {42}; + g<X>(); +} -- 2.43.0.254.ga26002b628