We're implementing [temp.param]/10 at parse time but not also at substitution time.
Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk? PR c++/61355 gcc/cp/ChangeLog: * pt.c (convert_template_argument): Perform array/function to pointer conversion on the substituted type of an NTTP. gcc/testsuite/ChangeLog: * g++.old-deja/g++.pt/nontype5.C: * g++.dg/template/param6.C: New test. --- gcc/cp/pt.c | 4 +++ gcc/testsuite/g++.dg/template/param6.C | 32 ++++++++++++++++++++ gcc/testsuite/g++.old-deja/g++.pt/nontype5.C | 2 +- 3 files changed, 37 insertions(+), 1 deletion(-) create mode 100644 gcc/testsuite/g++.dg/template/param6.C diff --git a/gcc/cp/pt.c b/gcc/cp/pt.c index 5af3a6472f8..170edbd6f1e 100644 --- a/gcc/cp/pt.c +++ b/gcc/cp/pt.c @@ -8528,6 +8528,10 @@ convert_template_argument (tree parm, else t = tsubst (t, args, complain, in_decl); + /* Perform array-to-pointer and function-to-pointer conversion + as per [temp.param]/10. */ + t = type_decays_to (t); + if (invalid_nontype_parm_type_p (t, complain)) return error_mark_node; diff --git a/gcc/testsuite/g++.dg/template/param6.C b/gcc/testsuite/g++.dg/template/param6.C new file mode 100644 index 00000000000..8306e753d70 --- /dev/null +++ b/gcc/testsuite/g++.dg/template/param6.C @@ -0,0 +1,32 @@ +// PR c++/61355 +// Verify we perform array-to-pointer and function-to-pointer conversion +// on the substituted/deduced type of an NTTP. + +int f(); +int p[5]; + +namespace cpp98 { + template<class T, T> struct X; + typedef X<int(), f> ty1; + typedef X<int[5], p> ty2; +} + +namespace cpp11 { +#if __cpp_variadic_templates + template<class T, T...> struct X; + using ty1 = X<int(), f>; + using ty2 = X<int[5], p>; +#endif +} + +namespace cpp17 { +#if __cpp_nontype_template_parameter_auto + template<decltype(auto)> struct X; + using ty1 = X<f>; + using ty2 = X<p>; + + template<decltype(auto)...> struct Y; + using ty3 = Y<f>; + using ty4 = Y<p>; +#endif +} diff --git a/gcc/testsuite/g++.old-deja/g++.pt/nontype5.C b/gcc/testsuite/g++.old-deja/g++.pt/nontype5.C index 2678cf78a7d..e24dca43622 100644 --- a/gcc/testsuite/g++.old-deja/g++.pt/nontype5.C +++ b/gcc/testsuite/g++.old-deja/g++.pt/nontype5.C @@ -19,5 +19,5 @@ static int g() { return f(); } int f() { return 0; } int main() { -return B<int,&f>::g(); // { dg-error "" } could not convert arg +return B<int,&f>::g(); } -- 2.33.0.664.g0785eb7698