Does C++ have "with" keyword like Pascal?

Probably the closest you can get is this: (this is just an academic exercise. Of course, you can't use any local variables in the body of these artificial with blocks!)

struct Bar {
    int field;
};

void foo( Bar &b ) {
    struct withbar : Bar { void operator()() {
        cerr << field << endl;
    }}; static_cast<withbar&>(b)();
}

Or, a bit more demonically,

#define WITH(T) do { struct WITH : T { void operator()() {
#define ENDWITH(X) }}; static_cast<WITH&>((X))(); } while(0)

struct Bar {
    int field;
};

void foo( Bar &b ) {
    if ( 1+1 == 2 )
        WITH( Bar )
            cerr << field << endl;
        ENDWITH( b );
}

or in C++0x

#define WITH(X) do { auto P = &X; \
 struct WITH : typename decay< decltype(X) >::type { void operator()() {
#define ENDWITH }}; static_cast<WITH&>((*P))(); } while(0)

        WITH( b )
            cerr << field << endl;
        ENDWITH;

no there is no such keyword.

I like to use:

    #define BEGIN_WITH(x) { \
        auto &_ = x;

    #define END_WITH() }

Example:

    BEGIN_WITH(MyStructABC)
    _.a = 1;
    _.b = 2;
    _.c = 3;
    END_WITH()