On Mon, Mar 30, 2026 at 10:26:45AM +0200, Tomasz Kaminski wrote:
> I would like to see tests of the following:
> namespace q {
> int foo();
> int bar();
>
> };
>
> [: (current_namespace() == ^^::) : ^^int : ^boo :]
> q::foo() {}
>
> auto q::bar()
> -> [: (current_namespace() == ^^q) : ^^int : ^boo :]
> {}
>
> struct X {
> struct Y {
> int foo();
> int bar();
> }
> };
>
>
> [: (current_class() == ^^X) : ^^int : ^boo :]
> X::Y:::foo() {}
>
> auto X::Y::bar()
> -> [: (current_class() == ^^Y) : ^^int : ^boo :]
> {}
>
> And some more test below.
So, I've tried to add the tests, tweaked syntax here and there.
The
typename [: current_class () == ^^X ? ^^int : ^^:: :]
X::Y:::foo ()
{
return 0;
}
test part fails, current_class () throws there because there
is no current class, are you sure that is not the desired behavior?
auto
Q::baz () -> typename [: current_namespace () == ^^Q ? ^^int : ^^:: :]
{
return 0;
}
part also fails, there I don't know what's right but possibly it should
be in Q; in that case it would be a pre-existing bug already for
std::meta::access_context::current () too.
> Could you add a test that includes the following?
> +struct W : T {}
> +{
> + info w = current_function ();
> +};
>
> void bar() {
> W w;
> w.t = is_constructor (w.t) && parent_of (w.t) == ^^T;
> w.w = is_constructor (w.t) && parent_of (w.t) == ^^W;
> W wb{};
> w.t = ^^bar;
> w.t = ^^bar;
> }
I've added that, but have no idea what you actually meant.
w.t and w.w are std::meta::info members, so assigning them
bool result? If you meant static_assert, then why is the
condition the same except ^^W vs. ^^T at the end and w would
need to be constexpr. wb is not used and what is the w.t == ^^bar;
testing?
> > --- gcc/testsuite/g++.dg/reflect/current_class1.C.jj 2026-03-27
> > 16:15:47.965107295 +0100
> > +++ gcc/testsuite/g++.dg/reflect/current_class1.C 2026-03-27
> > 17:14:36.688766585 +0100
> > @@ -0,0 +1,70 @@
> > +// { dg-do compile { target c++26 } }
> > +// { dg-additional-options "-freflection" }
> > +// Test std::meta::current_class.
> >
> For current_class, I think there is a subtle difference for functions
> defined out of line:
> Return // <-
So would you like some further tests or do you think some test is wrong?
Incremental diff:
--- gcc/testsuite/g++.dg/reflect/current_function1.C 2026-03-27
16:38:06.301962448 +0100
+++ gcc/testsuite/g++.dg/reflect/current_function1.C 2026-03-30
12:34:57.741967209 +0200
@@ -38,6 +38,11 @@
info v = current_function ();
};
+struct W : T
+{
+ info w = current_function ();
+};
+
void
bar ()
{
@@ -45,6 +50,7 @@
static_assert (foo (^^foo) == ^^foo);
static_assert (foo () == ^^bar);
static_assert (T {}.t == ^^bar);
+ static_assert (is_constructor (T ().t) && parent_of (T ().t) == ^^T);
consteval {
static_assert (current_function () == ^^bar);
consteval {
@@ -74,3 +80,14 @@
}
static_assert (baz ());
+
+consteval void
+fred ()
+{
+ W w;
+// static_assert (is_constructor (w.t) && parent_of (w.t) == ^^T);
+// static_assert (is_constructor (w.t) && parent_of (w.t) == ^^W);
+ W wb {};
+ w.t = ^^fred;
+ w.t = ^^fred;
+}
--- gcc/testsuite/g++.dg/reflect/current_class1.C 2026-03-27
17:14:36.688766585 +0100
+++ gcc/testsuite/g++.dg/reflect/current_class1.C 2026-03-30
12:38:53.809949829 +0200
@@ -68,3 +68,23 @@
static_assert (parent_of (current_class ()) == ^^bar);
};
}
+
+struct X {
+ struct Y {
+ int foo ();
+ int bar ();
+ };
+};
+
+typename [: current_class () == ^^X ? ^^int : ^^:: :]
+X::Y:::foo ()
+{
+ return 0;
+}
+
+auto
+X::Y::bar ()
+-> typename [: current_class () == ^^Y ? ^^int : ^^:: :]
+{
+ return 0;
+}
--- gcc/testsuite/g++.dg/reflect/current_namespace1.C 2026-03-27
16:38:23.647675541 +0100
+++ gcc/testsuite/g++.dg/reflect/current_namespace1.C 2026-03-30
12:39:23.662441717 +0200
@@ -92,2 +92,17 @@
}
+
+ int bar ();
+ int baz ();
+}
+
+typename [: current_namespace () == ^^:: ? ^^int : ^^:: :]
+Q::bar ()
+{
+ return 0;
+}
+
+auto
+Q::baz () -> typename [: current_namespace () == ^^Q ? ^^int : ^^:: :]
+{
+ return 0;
}
Jakub
