Re: ADL and C++0X Lambdas
On 12 Aug., 07:27, Jesse Perla <jessepe...@gmail.com> wrote:
Are there supposed to be some strange interactions with C++0X lambdas
and ADL? The following code, works in Intel 11.1 and GCC4.5 but fails
in VisualStudio 2010. Is this a Microsoft bug? If so, I posted it onhttps://connect.microsoft.com/VisualStudio/feedback/details/585643/bu...
if anyone wants to vote for it. Thanks
This link seems truncated and I could not successfully resolve it (not
even from your OP).
namespace X
{
struct Y{};
template<typename F>
void myfunc(F f, Y y) {}
}
[..]
int main()
{
[..]
myfunc([](double x){return x;}, X::Y()); //THIS FAILS! Doesn't seem
to like rvalue lambdas
auto f = [](double x){return x;};
myfunc(f, X::Y()); //Strangely, this works fine
}
The difference between these two invocations of myfunc looks
like a compiler bug to me. The compiler should accept both
versions. In fact the lambda closure case is not essentially
different from
struct { double operator()(double x) const { return x; } } obj;
myfunc(decltype(obj)(), X::Y());
within the function body of main. The conditions for
ADL require a function call (this is satisfied) and an
/unqualified-id/ as /postfix-expression/. This seems
to be satisfied as well. Comparing the mechanism of
ADL with the specification of a lambda-expression I
don't see a special interaction here, especially not
one related to the value category of the argument.
HTH & Greetings from Bremen,
Daniel Kr?gler
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