[Bug c++/65322] Narrowing conversion

[redi at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65322

--- Comment #2 from Jonathan Wakely <redi at gcc dot gnu.org> ---
N.B. to make the code compile just don't use braces for the initialization:

    : m_counter( b ? 1u : 0u )