[Bug c++/65786] Wrong code when using decltype to specify the return type

[glisse at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65786

--- Comment #4 from Marc Glisse <glisse at gcc dot gnu.org> ---
Compiling with -Wall -O prints:

w.cc: In function ‘int main()’:
w.cc:45:13: warning: ‘<anonymous>’ is used uninitialized in this function
[-Wuninitialized]
   cout << d.data << endl;   // bad: d.data == some random number.
             ^