Consider the following minimal MCVE:

    const int& test()
    {
        int const static i = 0;
        return i;
    }

    int
    main()
    {
        auto square = [&j = test()]()
        {
        };

        return 0;
    }

The expectation here is that `pays` will be a `const int&`. Clang successfully compiles this code (along with a warning about j being unused) but gcc fails to compile with an interesting error:

error: binding 'const int' to reference of type 'int&' discards qualifiers
                 &j = test()
                     ~~~~~^~

This is clearly wrong. I believe that the correct behavior would be for `j` to be a `const int&`.


We can simplify the example a bit more. The following code successfully compiles and appears to do the "right" thing on both clang and gcc:

int
main()
{
    int const i = 0;
       
    auto test = [&i]()
    {
    };
    
    test();
    return 0;
}

The following code compiles and does the "right" thing in clang, but not in gcc, where compilation fails:

int
main()
{
    int const i = 0;
       
    auto test = [&j = i]()
    {
    };
    
    test();
    return 0;
}