------- Comment #6 from fang at csl dot cornell dot edu 2009-02-09 17:21
-------
Subject: Re: std::mem_fun_ref fails to accept a member
function whose second argument with default value
> ------- Comment #5 from paolo dot carlini at oracle dot com 2009-02-09 16:47
> -------
> Your snippet boils down to this, which is clearly invalid:
>
> struct vector
> {
> void resize(long unsigned int, int = 0);
> };
>
> template<typename _Ret, typename _Tp, typename _Arg>
> void
> mem_fun_ref(_Ret (_Tp::*__f)(_Arg));
>
> void
> test() {
> mem_fun_ref(&vector::resize);
> }
Fair enough, that's what I wanted to know.
I suppose mem_fun_ref(&vector::resize) just *happened* to be accepted in
earlier versions of libstdc++, when it was never required to do so.
The following declaration was what allowed it to do so.
// 4.0.1 <bits/stl_vector.h>
// class vector {
void
resize(size_type __new_size)
{ resize(__new_size, value_type()); }
// };
Was there a compelling reason to remove it in favor of the unified
::resize(size_type, const value_type& t = T)?
Anyhow, thanks for the feedback!
Fang
--
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39136
