Does C++ have “with” keyword like Pascal?

Question

with keyword in Pascal can be use to quick access the field of a record. Anybody knows if C++ has anything similar to that?

Ex: I have a pointer with m

Answer 1

The following approach relies on Boost. If your compiler supports C++0x's auto then you can use that and get rid of the Boost dependence.

Disclaimer: please don't do this in any code that must be maintained or read by someone else (or even by yourself in a few months):

#define WITH(src_var)                                             \
    if(int cnt_ = 1)                                              \
        for(BOOST_AUTO(const & _, src_var); cnt_; --cnt_)


int main()
{
    std::string str = "foo";

    // Multiple statement block
    WITH(str)
    {
        int i = _.length();
        std::cout << i << "\n";
    }

    // Single statement block
    WITH(str)
        std::cout << _ << "\n";

    // Nesting
    WITH(str)
    {
        std::string another("bar");
        WITH(another)
            assert(_ == "bar");
    }
}