[cfe-dev] copy-list-initialization and converting constructors [over.match.list]

[Sebastian Redl]

On 18.05.2012, at 21:09, Fernando Pelliccioni wrote:

> Hi,
> 
> I have a doubt about this paragraph of [over.match.list] ...
> 
> "If the initializer list has no elements and T has a default constructor, the first phase is omitted. In copy-listinitialization,
> if an explicit constructor is chosen, the initialization is ill-formed. [ Note: This differs from
> other situations (13.3.1.3, 13.3.1.4), where only converting constructors are considered for copy-initialization.
> This restriction only applies if this initialization is part of the final result of overload resolution. —end note ]"
> 
> According to the above, what should be the result of compiling the following code?
> 
> struct my_string
> {
>   template<class InputIterator>
>   explicit my_string(InputIterator begin, InputIterator end);   // This is *not* a converting constructor.
> };
> 
> void foo( like_std_string );
> void foo( std::pair<std::string, std::string> );
> 
> void bar( my_string );
> void bar( std::pair<std::string, std::string> );
> 
> int main( /* int argc, char* argv[] */ )
> {
>   foo( {"k0", "v0"} );	// ambiguous in Clang (3.1) and GCC (4.7.1). OK, I think.
>   bar( {"k0", "v0"} );	// *Not* ambiguous in Clang. Ambiguous in GCC. Ambiguous to the Standard? I think should *not* be ambiguous.
Did you try this with the most recent SVN version? I'm pretty sure this was reported as a bug and fixed before the 3.1 branch even.

Sebastian

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20120520/f48cc3c3/attachment.html>