DESCRIPTION
The catchmark is used for building labels used for input-output of vector-valued fields (see field(2)):
cin >> catchmark("f") >> fh;
cout << catchmark("u") << uh
<< catchmark("w") << wh
<< catchmark("psi") << psih;
Assuming its value for output
is "u", the corresponding labels will be
"#u0", "#u1", "#u2", ...
IMPLEMENTATION
class catchmark {
public:
catchmark(const std::string& x);
const std::string& mark() const { return _mark; }
friend std::istream& operator >> (std::istream& is, const catchmark& m);
friend std::ostream& operator << (std::ostream& os, const catchmark& m);
protected:
std::string _mark;
};

