const reference binding to an rvalue
c++, c++11
Solution
A a(B());
is the declaration of a function named a returning an A and taking a pointer to a function without argument returning a B. See here. Add parenthesis and you'll get the error you expect:
A a((B()));
Problem
Working on this question, I found an inconsistent behavior. Why reference binding behave different in a constructor from a common function? ``` struct A { }; struct B : public A { B(){} private: B(const B&); }; void f( const B& b ) {} int main() { A a( B() ); // works A const & a2 = B(); // C++0x: works, C++03: fails f( B() ); // C++0x: works, C++03: fails } ``` I have tested it for C++03 with g++-4.1 and Comeau 4.2.45.2 in strict C++03 mode and with C++0x extensions disabled. I got same results. For C++0x was tested with g++-4.4 and Comeau 4.3.9 in relaxed mode and with C++0x extensions enabled. I got same results.