On Mon, 11 Jan 2010, vicente.botet wrote:
From: "Larry Evans" <cppljevans@suddenlink.net>
The .zip file in subject is here:
http://www.boostpro.com/vault/index.php?&directory=Input%20-%20Output
It includes a boost/iostreams/filter/indent.hpp and boost/iostreams/utility/indent_filtering_ostream.hpp.
The latter uses the former to allow indenting and undenting a stream.
On the example I see that the ++ and -- are not pairwised. int main(void) { boost::iostreams::indent_filtering_ostream<> mout(std::cout); mout<<"line1\n"; + ++mout; mout<<"line1.1"<<std::endl; + ++mout; mout<<"line1.1.1"<<std::endl; test_conversion(mout); - --mout; unsigned u=22; mout<<"line1.2:unsigned="<<u<<std::endl; float f=3.1416; mout<<"line1.3:float="<<f<<std::endl; - --mout; - --mout; mout<<"line2\n"; return 0; }
I wrote a similar utility, but made different tradeoffs. The basic usage looks like Indentation nl; // takes optional max depth and depth/level params Indentation::Indent in(nl); // could have used a reference notation Indentation::Outdent out(nl); std::ostream os; os << nl "class x << nl << '{' << in /* or nl.in */ << nl << "int x;" << nl << "int y;" << out << nl << "};" Rationale: - operator++ and operator-- don't mix "as expected" with operator<< - distinguishes between indenting and normal newlines - possible to maintain several indentation systems Later, Daniel