Even if they were explicit it wouldn't have "solved" his issue. Since he is using them in an if statement the C++ compiler would have considered that an explicit conversion anyway in C++0x mode.
I don't have a C++0x compiler handy, or I would test it, but I do believe explicit is only meant for cases such as this:
a + 1;
where a has a bool() operator that returns 1 or 0, in the old mode if there was no way to get a to be a number it would look at the operator bool() see that it returns a number and use that. Using explicit on the bool() operator would make that illegal and most likely a compiler error.
I don't have a C++0x compiler handy, or I would test it, but I do believe explicit is only meant for cases such as this:
a + 1;
where a has a bool() operator that returns 1 or 0, in the old mode if there was no way to get a to be a number it would look at the operator bool() see that it returns a number and use that. Using explicit on the bool() operator would make that illegal and most likely a compiler error.