What the #### is clang doing with inline namespaces???

[rare notch]

namespace n1
{
    inline namespace n2
    {
        class S1
        {
            public:
            int x = 0;
        };
    }
}




int main()
{
    n1::S1 instance;
    instance.y;
}

GCC result:

<source>: In function 'int main()':
<source>:20:14: error: 'class n1::n2::S1' has no member named 'y'
   20 |     instance.y;
      |              ^
Compiler returned: 1

Clang:

<source>:20:14: error: no member named 'y' in 'n1::S1'
   20 |     instance.y;
      |     ~~~~~~~~ ^
1 error generated.
Compiler returned: 1

How do I force clang to reveal the inline namespace in the types???

[zinc hawk]

When your question is answered use !solved to mark the question as resolved.

Remember to ask specific questions, provide necessary details, and reduce your question to its simplest form. For tips on how to ask a good question use !howto ask.

[stable lake]

try -fno-elide-type

[rare notch]

same thing

n2 is not shown

[stable lake]

then idk if you can show it

[rare notch]

even __PRETTY_FUNCTION__ with a type T doesn't reveal it

@civic wadi
Hey, you were bug reporting in clang,
got any ideas?

[warm steeple]

Clang drops the inline namespace in diagnostics only if the name is unambiguous without it.

;compile clang_trunk

namespace n1
{
    inline namespace n2
    {
        class S1
        {
            public:
            int x = 0;
        };
    }

    inline namespace n3
    {
        class S1
        {
            public:
            int x = 0;
        };
    }
}




int main()
{
    n1::n2::S1 instance;
    instance.y;
}

[rare pawn]

Compiler Output

<source>:28:14: error: no member named 'y' in 'n1::n2::S1'
   28 |     instance.y;
      |     ~~~~~~~~ ^
1 error generated.
Build failed

stablewasp_24259 | c++ | x86-64 clang (trunk) | godbolt.org

[rare notch]

oh...
so... is this gonna explode with C++26 compile time reflection?

[warm steeple]

how is that related?

btw. I looked at the source and I think there is currently no option to change that behavior for the user

if you want that then you'd have to file an issue for feature request I guess

[rare notch]

I thought C++26 grants you access to the class name and namespaces as some consteval string

[warm steeple]

I don't know what exactly reflection offers in that regard. I haven't spent much time looking at it yet.

[rare notch]

nah, I will just, run
clang++ -save-temps main.cpp
and watch the raw preprocessed code to reveal the real inline namespaces, with any insane attribute attached

[warm steeple]

But that doesn't matter here anyway, this is about the printing of compiler diagnostic messages.

What are you trying to do with the diagnostic message anyway that you care? It is meant to be read by a human, not machine processed. (There are other output options for that.)

[rare notch]

the real use case is,

when I want to forcefully declare a class duplicate to reveal the original one's implementation, and
::A::B::C::D::E::F::G::H variable;
and you have absolutely no clue, which ones are normal namespaces, which ones are implicit namespaces, which ones are classes/nested classes

so you gotta carefully do

namespace A
{
  class B
  {
    class C
    {

    };
  };
}

for example to trigger the duplicate and the compile error that spits out where the original is

[warm steeple]

Use clangd...

[rare notch]

clang what?

I use clang++

[warm steeple]

clangd is a LSP implementation for your IDE/editor based on clang

it has functionality to just tell you where e.g. a variable is declared/defined and other code browsing

[rare notch]

oh you mean intelisense? nahhhh, by the time I set up the lookup folders, it would be faster to just rip the declaration out of the source with grep

[warm steeple]

it is an alternative to intellisense, yes

you don't need to set up anything, you let your build system generate a compile_commands.json file, tell clangd/intellisense where that file is located and from there it just works

[rare notch]

if only you knew how insane our build tooling is...

[warm steeple]

even if the build system doesn't support it, there are tools like https://github.com/rizsotto/Bear which work pretty much universally

[rare notch]

!solved