Here we're rejecting the calls to g1 and g2 as ambiguous even though one overload is more constrained than the other (and otherwise equivalent), because the implicit 'this' parameter of the non-static overload causes cand_parms_match to think the function parameter lists aren't equivalent.
This patch fixes this by making cand_parms_match skip over 'this' appropriately. Note that this bug only occurs with non-template member functions because for the template case more_specialized_fns seems to already skips over 'this' appropriately. Bootstrapped and regtested on x86_64-pc-linux-gnu, does this look OK for trunk and perhaps 11? PR c++/103783 gcc/cp/ChangeLog: * call.c (cand_parms_match): Skip over 'this' when given one static and one non-static member function. Declare static. gcc/testsuite/ChangeLog: * g++.dg/cpp2a/concepts-memfun2.C: New test. --- gcc/cp/call.c | 17 ++++++++++--- gcc/testsuite/g++.dg/cpp2a/concepts-memfun2.C | 25 +++++++++++++++++++ 2 files changed, 39 insertions(+), 3 deletions(-) create mode 100644 gcc/testsuite/g++.dg/cpp2a/concepts-memfun2.C diff --git a/gcc/cp/call.c b/gcc/cp/call.c index 7f7ee88deed..ed74b907828 100644 --- a/gcc/cp/call.c +++ b/gcc/cp/call.c @@ -11918,7 +11918,7 @@ joust_maybe_elide_copy (z_candidate *&cand) /* True if the defining declarations of the two candidates have equivalent parameters. */ -bool +static bool cand_parms_match (z_candidate *c1, z_candidate *c2) { tree fn1 = c1->fn; @@ -11940,8 +11940,19 @@ cand_parms_match (z_candidate *c1, z_candidate *c2) fn1 = DECL_TEMPLATE_RESULT (t1); fn2 = DECL_TEMPLATE_RESULT (t2); } - return compparms (TYPE_ARG_TYPES (TREE_TYPE (fn1)), - TYPE_ARG_TYPES (TREE_TYPE (fn2))); + tree parms1 = TYPE_ARG_TYPES (TREE_TYPE (fn1)); + tree parms2 = TYPE_ARG_TYPES (TREE_TYPE (fn2)); + if (DECL_FUNCTION_MEMBER_P (fn1) + && DECL_FUNCTION_MEMBER_P (fn2) + && (DECL_NONSTATIC_MEMBER_FUNCTION_P (fn1) + != DECL_NONSTATIC_MEMBER_FUNCTION_P (fn2))) + { + /* Ignore 'this' when comparing the parameters of a static member + function with those of a non-static one. */ + parms1 = skip_artificial_parms_for (fn1, parms1); + parms2 = skip_artificial_parms_for (fn2, parms2); + } + return compparms (parms1, parms2); } /* Compare two candidates for overloading as described in diff --git a/gcc/testsuite/g++.dg/cpp2a/concepts-memfun2.C b/gcc/testsuite/g++.dg/cpp2a/concepts-memfun2.C new file mode 100644 index 00000000000..e3845e48387 --- /dev/null +++ b/gcc/testsuite/g++.dg/cpp2a/concepts-memfun2.C @@ -0,0 +1,25 @@ +// PR c++/103783 +// { dg-do compile { target c++20 } } + +template<bool B> +struct A { + template<class...> void f1() = delete; + template<class...> static void f1() requires B; + + template<class...> void f2() requires B; + template<class...> static void f2() = delete; + + void g1() = delete; + static void g1() requires B; + + void g2() requires B; + static void g2() = delete; +}; + +int main() { + A<true> a; + a.f1(); // OK + a.f2(); // OK + a.g1(); // OK, previously rejected as ambiguous + a.g2(); // OK, previously rejected as ambiguous +} -- 2.34.1.428.gdcc0cd074f