Hi, Now I'm looking at Phoenix and Lambda libraries. Could somebody explain why Lambda allows to use the following expression: void foo(int) { ... } ... bind(foo, _1)(10);
yet Phoenix does not. Phoenix requires to use helper variable: void foo(int) { ... } ... int i = 0; bind(foo, _1)(i);
I've read document about "Forwarding Function Problem" (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2002/n1385.htm). I understand the core issue, but how does Lambda.bind solve it?
Lambda takes by value, Phoenix takes by reference.
Both Lambda and Phoenix pass arguments by reference or by const reference. Moreover if I write following code it compiles fine: int add(int a, int b) { return a + b; } void bind_expression() { const int i = 5; cout << bind(add, _1, _2)(i, i) << endl; cout << bind(add, _1, _2)((const int&)10, i) << endl; } But if I change second 'bind' to (type cast is removed): cout << bind(add, _1, _2)(10, i) << endl; compilation failes. For me it's kind of magic. I use boost 1.39 and my compiler - g++ 4.3.1 Regards, Alexey.